JP2007233782A - Control method for heating value, and computer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress reduction of performance small while suppressing heat generation of a heat generating device. <P>SOLUTION: A power consumption value and a temperature value of a processor are periodically measured to the heat generating device incorporating a processor allowing a change of a maximum power consumption value. When a value representing the set of the plurality of measured power consumption values exceeds a prescribed threshold value and when the temperature value exceeds a prescribed value, it is detected that a high heating-value state of the processor continues over a prescribed time, and the maximum power consumption value of the processor is reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique for controlling the amount of heat generated in a computer, and more particularly to a technique for suppressing a decrease in performance while suppressing heat generation of a processor.

  A personal computer (hereinafter referred to as a PC) has many devices such as a CPU and a video card mounted inside a casing. Each device generates heat and the temperature rises as it continues to operate. Some of the major devices generate a large amount of heat, and if the temperature rises too much, they may interfere with operation, or in the worst case, burn out (hereinafter these devices are collectively referred to as exothermic devices). ). For this reason, in a heat-generating device that is an integrated circuit having a built-in processor such as a CPU or a video chip, a temperature sensor is usually integrated in a die. The PC performs thermal management based on the temperature measured by the temperature sensor built in these exothermic devices so that the temperature of the device does not rise too much. There are two types of thermal management for suppressing the rise in temperature. One is control of a mechanism that discharges heat to the outside of the housing, such as a cooling fan. The other is control that lowers the performance of the heat generating device and reduces the amount of heat generation.

  Among them, a technique called SpeedStep (registered trademark) is known as a technique for controlling the performance of the CPU of the PC. SpeedStep is a technology developed by Intel Corporation that switches the voltage and operating frequency during CPU operation. The extended version of SpeedStep, which is generally used on current PCs, has a set of voltage and operating frequency in several to tens of steps, and the voltage and operating frequency can be changed according to the CPU load. (Hereafter, it is called SpeedStep in the meaning including the extended version SpeedStep). It is possible to reduce the actual CPU operating frequency by designating the maximum operating frequency allowed at that time from the outside. In addition, the voltage is reduced as the operating frequency is reduced. If the voltage and operating frequency of the CPU are reduced, the power consumption and heat generation of the CPU are also reduced. The lowest maximum operating frequency is about half of the highest maximum operating frequency. Hereinafter, setting the maximum operating frequency during the operation of the processor to be lower than the highest operating frequency possible with the processor is referred to as clipping.

  Further, ACPI (Advanced Configuration and Power Interface) is known as a standard for controlling the power supply of the PC. This standard was developed by Intel Corporation, Microsoft Corporation US, and Toshiba Corporation as a unified system for managing the power consumption of each component of the PC in cooperation with BIOS. The OS can finely set and manage various functions and operations related to the control of power consumption of each component such as power on / off, suspend / resume, and fan control. Since version 2.0 published in 2000, ACPI has officially supported clip operation by SpeedStep.

As a technique for controlling the voltage and operating frequency of the CPU, for example, there are the following documents. Patent Document 1 is a patent application filed by Intel Corporation, and discloses a technique for controlling the voltage and operating frequency of a CPU based on the temperature or power consumption of the CPU. Patent Document 2 discloses a technique for constantly measuring power supplied to a CPU and controlling the voltage and operating frequency of the CPU based on the measured power. Patent Document 3 discloses a technique for obtaining high performance even for a PC using a battery with low discharge power by temporarily switching the CPU to a high performance operation mode and then switching to a low performance operation mode. .
Special Table 2002-529806 JP 2004-133646 A JP 2005-182522 A

  A notebook / book PC (hereinafter referred to as a notebook PC) has a smaller space inside the housing as the size of the housing becomes smaller. Therefore, the amount of heat that can be discharged outside the housing by a cooling fan or the like is larger than that of a desktop PC. Strictly limited. Therefore, it is necessary to select an exothermic device that can be mounted inside according to the exhaust heat capacity of the housing. It is not usually possible to mount a CPU whose TDP (Thermal Design Power), which is an index value indicating the maximum amount of heat generated by the CPU, exceeds 20 W in a casing whose rated value of heat exhaust capability is 20 W. In particular, in a notebook PC, the exhaust heat capacity of the casing and the TDP of the CPU tend to be close to each other.

  In particular, a notebook PC having a subminiature casing called a sub-notebook type has a particularly low heat exhaustion capability, and therefore often has a low power consumption type CPU having a small TDP or a CPU called an ultra low power consumption type. However, the low power consumption type CPU is more expensive than the normal type CPU, and its performance is limited to be low. For example, the Pentium (registered trademark) M processor of Intel Corporation, one of the representative products for CPUs for notebook PCs, has a maximum operating frequency of up to 2.26 GHz, while it is a low power consumption type. Is up to 1.6 GHz, and the ultra-low power consumption type is up to 1.3 GHz. In other words, the smaller the size of the housing, the lower the performance, and the higher the cost.

  However, the amount of heat generated from the CPU greatly depends on the load and duration of the CPU. Therefore, even if the CPU has a TDP of 30 W, the actual amount of heat of 30 W is not always generated. While heat generation of about 30 W is observed when the maximum load is applied to the CPU, the heat generation amount is 1 W or less at low load. In a general office or home PC usage situation, the high load on the CPU is often temporary, and the high load is rarely kept for a long time. Therefore, if the exothermic device can be clipped by the above-described SpeedStep to suppress heat generation, it becomes possible to mount an exothermic device having a TDP exceeding the exhaust heat capability in a casing having a low exhaust heat capability. . At that time, if a temperature sensor built in the device is used, the temperature of the device in operation can be easily measured.

  However, a problem in that case is that there is a slight time lag between the time when the exothermic device is clipped and the temperature drops. In the conventional method, when the temperature value measured by a temperature sensor built in the device exceeds a specific threshold, the device is clipped to suppress heat generation. At this time, it takes some time until the temperature value starts to drop after clipping. For this reason, in order not to exceed the temperature at which the operation of the notebook PC is actually adversely affected, it is necessary to set the threshold value for determining whether or not to clip to a lower temperature. As a result, in the conventional method, the performance of the device has been reduced more than necessary.

  Further, the conventional method does not consider the influence between devices in the temperature measurement. For example, even when a high load is applied to the CPU and the amount of heat generated is high, the load applied to the video chip is low and the amount of heat generated is low. However, since the CPU and the video chip are often arranged close to each other in a small casing, if the heat generation amount of the CPU is high, the temperature of the video chip rises due to the heat generated from the CPU. To do. In addition, only with the temperature measured by the temperature sensor built in the video chip, this temperature rise is due to heat generated by the operation of the video chip itself, or due to the influence of heat from the surroundings such as the CPU. I can't tell if it is. For this reason, although it is not actually necessary to suppress the heat generation of the video chip, the performance of the video chip is lowered in the conventional method.

  Further, the conventional method does not consider the influence of the ambient temperature around the PC. The rated value of the exhaust heat capacity of the housing is designed on the assumption that it operates at an environmental temperature of 25 ° C to 28 ° C. For example, when the environmental temperature is higher than those temperatures, even if the amount of heat generated from the exothermic device is small, the temperature of the device may reach a threshold for determining whether or not to clip. Even in such a case, the performance of the device has been lowered by the conventional method even though it is not actually necessary to suppress the heat generation of the device.

  Accordingly, an object of the present invention is to provide a method and a computer for controlling the amount of heat generated by a heat-generating device that can suppress a decrease in performance while suppressing heat generation from a heat-generating device of a PC.

  In the heat generation amount control method according to the present invention, a computer equipped with a heat generating device that is an integrated circuit including a processor capable of changing the maximum power consumption value controls the heat generation amount of the processor. In this control method, while operating the processor, the power consumption value and the temperature value of the processor are periodically measured, and a value representing a set of the measured power consumption values exceeds a predetermined threshold value. When the temperature value exceeds a predetermined threshold, the maximum power consumption value of the processor is reduced. The value representative of the set of power consumption values here is, for example, an average value, a maximum value, a median value, or the like of a plurality of power consumption values that are continuous in a certain time range. By using such a representative value for judgment, noise associated with load fluctuations can be eliminated and the maximum power consumption value of the processor can be reduced more than when judging simply by fluctuations in power consumption values. Can be done appropriately.

  If the state of high heat generation of the exothermic device ends in a short time, the generated heat is directly exhausted outside the housing by a cooling fan or the like, so that the influence on the temperature rise of the exothermic device is small. The temperature rise of the exothermic device is affected when a state of high heat generation continues for a certain time. On the other hand, the power consumption value of the processor is closely related to the amount of heat generated from the exothermic device, and the time lag is small compared to the relationship between the temperature of the device and the amount of heat generated. For this reason, a value representing a set of a plurality of power consumption values measured periodically exceeds a predetermined threshold means that the processor has a high heat generation state for a certain period of time. . If the maximum power consumption value of the processor is reduced when this state is detected, the amount of heat generation can be reduced at a more appropriate timing, and the temperature rise of the device can be suppressed. Furthermore, by using the power consumption value and the temperature value in combination, it is possible to appropriately detect the heat generation of the device itself, so that it is difficult to be affected by surrounding devices and the environmental temperature.

  At this time, in order to reduce the maximum power consumption value of the processor, it is effective to clip the processor and suppress the maximum operating frequency. In addition, if a moving average is obtained from representative values of a plurality of measured power consumptions per unit time, when the moving average exceeds a threshold value a predetermined number of times continuously, the processor generates a large amount of heat. Can be detected more appropriately for a certain period of time. Therefore, it is desirable to calculate the representative value of power consumption used for each unit time by using an average value of values obtained by sampling a current value that can be easily measured a predetermined number of times.

  As described above, the processor is provided with a maximum operating frequency of several to tens of steps. Therefore, if the temperature rise can be suppressed by clipping the processor and lowering the maximum operating frequency by one step, the operation can be continued as it is. However, even if the maximum operating frequency is lowered by one step, the temperature of the processor does not change. If it continues to rise, the maximum operating frequency can be further reduced until the temperature does not rise. If one processor has already reached the lowest maximum operating frequency from which it is impossible to further reduce the maximum operating frequency, another processor may be clipped. For example, if it is impossible to further reduce the maximum operating frequency of the CPU, the video chip can be clipped to suppress heat generation.

  For the measurement of the power consumption value and temperature value of the processor as described above, when the temperature of the processor is low, the unit time for measurement is set long, and the temperature value measured when the temperature of the processor starts to rise When the value exceeds a predetermined value, the unit time can be set short. Of course, the temperature value when the measurement unit time is set short is lower than the temperature value when the processor is clipped.

  In addition, when the moving average of the measured power consumption continuously falls below a predetermined value for a predetermined number of times, it can be determined that the state where the processor generates a large amount of heat has been eliminated. The maximum operating frequency during operation of the processor can be returned to the highest operating frequency possible with the processor. This also leads to minimizing performance degradation.

  The features described above are provided not only as a method for controlling the amount of heat generated inside the computer, but also as a computer capable of executing such a control method. The frequency control set power value and the frequency control set temperature value, which are threshold values for controlling the maximum operating frequency during the operation of the processor, are stored in the computer as a thermal action table. Examples of the exothermic device to be controlled include a CPU and a video chip, but are not necessarily limited thereto. In addition, the temperature of these exothermic devices can be measured more appropriately by using a temperature sensor integrated in the die during the manufacture of the integrated circuit, and the temperature sensor can be measured from outside the device. There is no need to add. Furthermore, although the computer is equipped with a cooling fan, the rotational speed of the cooling fan and the maximum operating frequency of the processor can be controlled separately.

  According to the present invention, it is possible to provide a method for controlling the amount of heat generated by a heat generating device and a computer that can suppress a decrease in performance while suppressing heat generated by the heat generating device of the PC.

  FIG. 1 is an outline view of a notebook PC 10 according to an embodiment of the present invention, and FIG. 2 is a schematic block diagram showing its system configuration. The notebook PC 10 is composed of a casing 13 having a keyboard mounted on the surface thereof and housing many devices therein, and a liquid crystal display (LCD) 11. Various devices shown in FIG. 2 are mounted inside the housing 13. The CPU 15 is an arithmetic processing unit having a central function of the notebook PC 10 and executes an OS, a BIOS, a device driver, an application program, or the like. The CPU 15 includes an FSB (Front Side Bus) 17 as a system bus, a PCI (Peripheral Component Interconnect) bus 19 for performing communication between the CPU 15 and peripheral devices, and an LPC (Low Pin Count) which is an interface replacing the ISA bus. ) Signals are transmitted and received by being connected to each device through a bus 20 of three stages. A temperature sensor 53a for monitoring the CPU 15 is formed in the die of the CPU 15 as an embedded type. A signal output from the temperature sensor 53a is connected to an A / D input of an embedded controller 47 described later.

  The FSB 17 and the PCI bus 19 are connected by a CPU bridge 21 called a memory / PCI chip. The CPU bridge 21 includes a memory controller function for controlling an access operation to the main memory 23, a data buffer function for absorbing a difference in data transfer speed between the FSB 17 and the PCI bus 19, and the like. It has a configuration. The main memory 23 is a writable memory used as a reading area for a program executed by the CPU 15 and a work area for writing processing data. The video chip 25 receives a drawing command from the CPU 15, generates an image to be drawn, writes it in a VRAM (not shown), reads it from the VRAM, and sends it to the display 11 as drawing data. Similarly to the CPU 15, a temperature sensor 53b for monitoring the video chip 25 is formed in the die of the video chip 25 as an embedded type. A signal output from the temperature sensor 53b is also connected to an A / D input of an embedded controller 47 described later.

  An I / O bridge 27, a CardBus controller 29, a miniPCI slot 35, and an Ethernet (registered trademark) controller 39 are connected to the PCI bus 19. The CardBus controller 29 is a controller that controls data transfer between the PCI bus 19 and the PC card 33. A CardBus slot 31 is connected to the CardBus controller 29, and a PC card 33 is inserted into the CardBus slot 31. For example, a mini PCI card 37 with a built-in wireless LAN module is mounted in the mini PCI slot 35. The Ethernet controller 39 is a controller for connecting the notebook PC 10 to the LAN.

  The I / O bridge 27 has a bridge function between the PCI bus 19 and the LPC bus 20. The I / O bridge 27 has an IDE (Integrated Device Electronics) interface function, and is connected to a hard disk drive (HDD) 43 and an optical drive 45 (CD drive, DVD drive, etc.). A USB connector 41 is connected to the I / O bridge 27. An embedded controller 47, a BIOS flash ROM 57, and an I / O controller 59 are connected to the LPC bus 20. An I / O connector 60 is connected to the I / O controller 59.

  The embedded controller 47 is a microcomputer composed of a CPU, a ROM, a RAM, and the like, and further includes a plurality of channels of A / D input terminals, D / A output terminals, and digital input / output terminals. The embedded controller 47 is connected to the cooling fan 49, the temperature sensors 53a to 53c, and the power supply device 55 through their input / output terminals. The temperature sensor 53 is provided for each main device for monitoring the temperature of each device, and is arranged in the vicinity of the device to be monitored as an external type or formed in the die of the device as an embedded type. Is done. The temperature sensor 53a for monitoring the CPU 15 and the temperature sensor 53b for monitoring the video chip 25 are embedded as described above. Other devices and the temperature sensor 53c that monitors the inside of the housing are arranged in the vicinity of each device that is a target of temperature monitoring.

  The embedded controller 47 can individually control the cooling fan 49 and the power supply device 55 based on the temperature values detected by the temperature sensors 53a to 53c. The cooling fan 49 is controlled to be turned on / off and the number of revolutions based on a control signal sent from the embedded controller 47, and the notebook PC 10 is forcedly cooled by taking outside air into the housing 13 and exhausting internal heat. Cooling. Control of the cooling fan 49 by the embedded controller 47 is performed completely separately from control of the operating frequency and voltage of the CPU 15 and the video chip 25 described later. The power supply device 55 includes an AC adapter (not shown), a battery (not shown), a DC-DC converter, and a regulator. The DC-DC converter and the regulator will be described later.

  FIG. 3 shows a configuration of a device that realizes switching of the operating frequency and voltage of the CPU 15 and the video chip 25 that are heat generating devices to be controlled in the amount of heat generation in the notebook PC 10 according to the embodiment of the present invention. It is a block diagram shown about. The DC-DC converter 61 converts electric power supplied from an AC adapter or a battery (both not shown) into direct current of a predetermined voltage and supplies it to each device in the notebook PC 10. The power supplied from the DC-DC converter 61 to the CPU 15 is subjected to pulse width modulation by the regulator 63a, and the operating frequency and voltage are determined and supplied to the CPU 15. Similarly, the power supplied from the DC-DC converter 61 to the video chip 25 is subjected to pulse width modulation by the regulator 63b, and the operating frequency and voltage are determined and supplied to the video chip 25. Incidentally, a technique for determining the operating frequency and voltage by pulse width modulation is already known, for example, from Japanese Patent Application Laid-Open No. 2003-88110.

  The embedded controller 47 can clip the CPU 15 by sending a control signal designating the maximum operating frequency to the operating frequency and voltage of the CPU 15 determined by the regulator 63a. The embedded controller 47 can also clip the video chip 25 by sending a control signal designating the maximum operating frequency with respect to the operating frequency and voltage of the video chip 25 determined by the regulator 63b.

  Sense resistors 65a and 65b are connected between the regulator 63a and the CPU 15 and between the video chip 25 and the regulator 63b, respectively. The voltage across each of the sense resistors 65a and 65b is input to the A / D input terminal of the embedded controller 47, whereby the embedded controller 47 independently determines the current value supplied to the CPU 15 and the video chip 25. Can be measured. Since the voltage is a constant value determined by the regulators 63a and 63b, the power consumed by the CPU 15 and the video chip 25 can be grasped in real time if the current value can be measured. Further, the voltage output from the temperature sensor 53 a for monitoring the CPU 15 and the temperature sensor 53 b for monitoring the video chip 25 are also input to the A / D input terminal of the embedded controller 47, and thereby the embedded controller 47. Can measure the temperature of the CPU 15 and the video chip 25 independently.

  Each device constituting the notebook PC 10 described above, and an OS (Operating System) and a BIOS (Basic Input / Output System) operating on the notebook PC correspond to ACPI and SpeedStep. The OS is read from the HDD 43, and the BIOS is read from the BIOS flash ROM 57, and each operates on the CPU 15. The BIOS includes a thermal action table that stores threshold values used in a program described later. On the other hand, in the embedded controller 47, firmware for measuring temperature and power consumption operates for each of the CPU 15 and the video chip 25. Regarding the temperature and power consumption of the CPU 15 and the video chip 25 measured by the embedded controller 47, calculation and determination as described later are performed by the BIOS, and based on the determination result, the BIOS sends the CPU 15 and the video chip to the OS. Request to clip 25. Based on a request from the BIOS, the OS clips the CPU 15 and the video chip 25 via the embedded controller 47 based on the ACPI standard method.

  That is, in the case of a PC having hardware, OS and BIOS corresponding to ACPI and SpeedStep, the firmware of the BIOS and embedded controller 47 is partially changed, and each of the CPU 15 and the video chip 25 is described in FIG. It is possible to implement the present invention at low cost simply by adding a means for measuring power consumption such as the sense resistor 65. Note that the sharing of operations among the OS, the BIOS, and the embedded controller is an item that can be arbitrarily selected by those skilled in the art, and the above-described embodiment is merely an example. For example, there may be an embodiment in which measurement, calculation and determination are performed only by the embedded controller.

  Incidentally, FIGS. 2 and 3 merely show a simplified configuration and connection relationship of main hardware in order to explain the present embodiment. Many other devices are used to configure the notebook PC 10, but these are well known to those skilled in the art and will not be described in detail. Of course, a person skilled in the art also arbitrarily selects a plurality of blocks described in FIGS. 2 and 3 as one integrated circuit or conversely divides one block into a plurality of integrated circuits. To the extent possible, it is included in the scope of the present invention.

  FIG. 4 is a flowchart showing a program related to the control of the amount of heat generated by the BIOS. This program is started as soon as the notebook PC 10 starts operating (block 101) and is executed in a cycle of about 4 to 5 seconds. The embedded controller 47 measures the temperature of the CPU 15 by the temperature sensor 53a built in the CPU 15 (block 103). Further, the embedded controller 47 measures the power consumption of the CPU 15 through the voltage across the sense resistor 65a (block 105). Here, it is determined whether or not the current temperature of the CPU 15 exceeds the threshold value T1 (block 107). If the temperature of the CPU 15 exceeds the threshold value T1, the Thermal Caution Mode program described in FIG. 5 is started (block 109) and the process ends (block 111). If the temperature of the CPU 15 does not exceed the threshold value T1 in block 105, the program continues to be executed in the same cycle thereafter.

  FIG. 5 is a flowchart showing a thermal caution mode program related to the control of the amount of heat generated by the BIOS. This program is executed at a cycle of about 1 second earlier than the program of FIG. 4 (block 201). The temperature of the CPU 15 (block 203) and the measurement of power consumption (block 205) are the same as the program of FIG. However, an x second moving average is calculated from the measured power consumption. From there, it is first determined whether or not the x-second moving average of power consumption is below y1 continuously for y1 times (block 207). Z1 is a threshold value for determining whether or not the power consumption is low. What is determined here is whether or not the CPU 15 has been in a low power consumption state for a certain period of time. If the power consumption continues to be low for a certain period of time, the calorific value is small and the temperature does not rise. Therefore, the clip mode described after the CPU 15 and the video chip 25 is canceled (block 209), and Thermal Caution Mode Is terminated (block 210) and the program returns to the program of FIG. 4 (block 249).

  Here, a state in which the CPU 15 is clipped, that is, a state in which the maximum operating frequency is set to a value lower than the highest frequency at which the CPU can operate is referred to as a clip mode. Canceling the clip mode means returning the maximum operating frequency to the highest frequency at which the CPU can operate. And when the CPU has a maximum operating frequency of several to tens of steps, setting the maximum operating frequency to a value that is one step lower than the current value is said to increase the clip by one step. Setting the frequency to a value one step higher than the current value is referred to as one-step unclip.

  If it is determined in block 207 that the CPU 15 has not been in a state of low power consumption for a certain time or longer, it is determined whether the CPU 15 is currently in the clip mode (block 211). If the current clip mode is not set, it is determined whether the CPU 15 needs to be set to the clip mode. The judgment condition is that the temperature of the CPU exceeds the threshold value T2 (block 213), and the x-second moving average of power consumption continuously exceeds y2 for y2 times (block 215). Here, T2> T1 and Z2> Z1. When both the temperature and power consumption conditions are satisfied, the condition where the power consumption is high and the heat generation amount is large for a certain period of time and the temperature of the CPU 15 rises is satisfied. The mode is set (block 217), and one-stage clip is increased (block 223). At that time, the current temperature is stored as a variable T3 (block 225), and the program is continuously executed in the same cycle. If one or both of the temperature and power consumption conditions are not satisfied, it is determined that the CPU 15 does not need to be in the clip mode, and the program continues to be executed at the same cycle.

  If it is determined in block 211 that the CPU 15 is currently in the clip mode, whether the current temperature of the CPU is higher (block 227) or lower than the temperature T3 of the CPU in the previous cycle (Block 229) is determined. If the temperature is falling, the CPU or video chip 25 is clipped one step (block 231), the current temperature is stored as a variable T3 (block 225), and the program continues to be executed in the same cycle. If the temperature has risen, it is first determined whether or not the CPU can increase the clip by one step (block 219), and if possible, the clip is increased by one step (block 223). This is stored as a variable T3 (block 225), and the program is continuously executed at the same cycle. The current temperature stored as the variable T3 is used in the next cycle. By this process, if the CPU 15 simply increases the clip by one step, it is not sufficient to decrease the temperature of the CPU, and the clip increase can be repeated until the temperature of the CPU decreases.

  If it is determined in block 219 that the current maximum operating frequency of the CPU 15 is the lowest value possible with the CPU and no further clip increase is possible, the video chip 25 It is determined whether or not it is possible to increase the clip by one step (block 241). If it is determined that the video chip can increase one-stage clip (step 243), the current temperature is stored as a variable T3 (block 245), and the program is executed at the same cycle. to continue. It should be noted that the parameters set in the above flowcharts, such as the temperature and power consumption measurement intervals, the moving average seconds, the time and power consumption threshold values, etc., are arbitrary values based on experiments or experience by those skilled in the art. Can be set.

  As described above, since the power consumption can be measured separately for the CPU 15 and the video chip 25, it is determined separately for each of the CPU and the video chip whether or not the condition for increasing the temperature is satisfied. The clip increase and release processes can be performed separately. In reality, however, there are many states where the power consumption of the CPU 15 is high and the power consumption of the video chip 25 is low, whereas there is a state where the power consumption of the video chip 25 is high and the power consumption of the CPU 15 is low. There are few. Therefore, in the present embodiment, when the temperature of the CPU 15 rises, the CPU 15 is first given priority to the clip mode, and when the temperature rise cannot be suppressed only by the clip of the CPU 15, the video chip 25 is put into the clip mode. When the clip mode of the CPU 15 is released in block 209, the clip mode of the video chip 25 is also released at the same time.

  In block 241, the current maximum operating frequency for the video chip 25 is the lowest value possible for the video chip, and it is impossible to increase the clip any more. If it is determined that the temperature rise of the CPU 15 does not stop, there is a possibility that some abnormality has occurred in the device or the cooling fan 49, so an abnormality process is performed (block 247) and the program is terminated (block 249). . In the abnormal process, a warning is displayed on the display 11 of the notebook PC 10, and the maximum operating frequency of the CPU is suppressed to about one third of the maximum value by throttling which is a known technique, or the notebook PC 10 is currently operating on the notebook PC. This is processing such as saving the OS and application software data, and then shutting down the power of the notebook PC.

  FIG. 6 is a notebook PC equipped with a CPU having a maximum operating frequency of 1.60 GHz, and the CPU and video chip when the maximum operating frequency is fixed at 1.60 GHz and the benchmark is executed without controlling the heat generation amount. It is a graph which shows the change of temperature and power consumption. This benchmark is a program that allows a PC to execute processing assuming the use of a PC in a general office and score the PC performance.

  According to the graph of FIG. 6, the CPU temperature 301 and the video chip temperature 303 both rise to around 62 degrees Celsius, and these temperatures rise and fall at approximately the same timing. However, on the other hand, it can be seen that the value of the power consumption 305 of the CPU is large and fluctuates, while the value of the power consumption 307 of the video chip is small and varies little. In other words, it can be seen that the temperature rise of the video chip is mainly due to the influence of heat generated by the CPU, and the heat generated by the video chip itself is small. Further, when the timings 311a to 311d in which the state of high power consumption of the CPU continues for a certain degree or more and the timings 313a to 313d at which the temperature of the CPU rises are compared, the state of 313a is slightly delayed from the state of 311a. The same applies to the comparison between 311b to 311d and 313b to 313d. On the other hand, when the state in which the power consumption of the CPU is high occurs only in a discrete manner, the temperature of the CPU decreases slightly later. Hereafter, the target is to keep the temperature of the CPU and video chip at around 55 degrees Celsius.

  7 and 8 are diagrams showing the results of CPU clipping performed by the conventional technique on the same notebook PC as FIG. FIG. 7 is a flowchart showing a program used when the CPU is clipped by the prior art. Compared with the program executed by the BIOS when in the thermal caution mode in the embodiment described in FIG. 5, there are the following differences. In the prior art, there is no measurement of the power consumption of the CPU and the video chip, and therefore it is naturally not determined using the power consumption. Further, the CPU clip mode has only two levels of the maximum value and the minimum value of the maximum operating frequency. In addition, the video chip is not put into clip mode. Once started, the CPU temperature is measured (blocks 201 'to 203'). If the measured temperature falls below the temperature T1 (block 207 '), the clip mode is canceled (block 209') and Thermal Caution Mode is terminated. (Blocks 210 ′ and 249 ′) When the temperature T2 is exceeded (Block 213 ′), the CPU is set to the clip mode (the minimum value of the maximum operating frequency) (Block 217 ′). In other words, here, the operation of clipping the CPU is determined only by the temperature without using the power consumption. Here, T2 = 55 degrees Celsius. The program that operates when not in the Thermal Caution Mode is the same as FIG.

  FIG. 8 shows a change in the temperature and power consumption of the CPU and the video chip when the same benchmark as in FIG. 6 is executed by applying the conventional heat generation amount control shown in FIG. It is a graph which shows the change of the maximum operating frequency of CPU. According to the changes in temperature and power consumption shown in FIG. 8A, the goal of reducing the CPU temperature 401 and the video chip temperature 403 to around 55 degrees Celsius has been achieved. Further, fluctuations in the CPU power consumption 405 are suppressed compared to the power consumption 305 shown in FIG. Incidentally, the point that the fluctuation of the power consumption 407 of the video chip is small is the same as the power consumption 307 shown in FIG. However, according to the change 409 in the maximum operating frequency of the CPU shown in FIG. 8B, there is little time for operating at 1.60 GHz which is the maximum value of the maximum operating frequency, and the maximum operating frequency 1 below that. .Many hours of operation at 33 GHz or lower.

  FIG. 9 shows the CPU and video chip temperature and power consumption when the CPU of the present embodiment shown in FIG. 5 is applied to the same notebook PC as in FIG. 6 and the same benchmark as in FIG. 6 is executed. 6 is a graph showing changes in the CPU and changes in the maximum operating frequency of the CPU. In the Thermal Caution Mode, the CPU and video chip temperature and power consumption are measured at 1 second intervals. When the temperature exceeds 55 degrees Celsius and the 2-second moving average of the power consumption of the CPU exceeds 8 W on average three consecutive times, the CPU starts the operation in the clip mode. That is, in FIG. 5, T2 = 55 degrees Celsius, x = 2 seconds, y2 = 3 times (6 seconds), and Z2 = 8 W. According to the changes in temperature and power consumption shown in FIG. 9A, the target of reducing the CPU temperature 501 and the video chip temperature 503 to around 55 degrees Celsius is almost achieved. Further, the power consumption 505 of the CPU and the power consumption 507 of the video chip are similar to the tendency shown in FIG. However, according to the change 509 in the maximum operating frequency of the CPU shown in FIG. 9B, the operating time at 1.60 GHz which is the maximum value of the maximum operating frequency is that of the prior art shown in FIG. It is longer than the case. On the other hand, the time during which the maximum operating frequency is 1.33 GHz or less is shorter than that in FIG.

  FIG. 10 shows the case where the maximum operating frequency is not controlled (FIG. 6), the case where the maximum operating frequency is controlled only by the temperature of the prior art (FIG. 8), and the case of the present embodiment (FIG. 9). Is a table showing a comparison of performance obtained by running the benchmarks described above. In the figure, scores for each of two-dimensional drawing (2D), three-dimensional drawing (3D), and web browsing (Web), a total score (total), and a time when the CPU operates at each maximum operating frequency. (%) And the temperature of the CPU. Of course, the faster the execution speed, the higher the score. In the case where control is not performed for the maximum operating frequency shown as (A) in FIG. 10 (FIG. 6), the maximum operating frequency of the CPU is fixed to the maximum value of 1.60 GHz. Is expensive. However, as described above, the temperature rise of the CPU and the video chip is not suppressed.

  On the other hand, when the maximum operating frequency of the CPU is controlled only by the temperature of the prior art shown as (B) in FIG. 10 (FIG. 8), and the maximum operating frequency of the CPU according to the present embodiment shown as (C). Compared with the case where the control is performed (FIG. 9), as described above, both of the targets for suppressing the temperature of the CPU and the video chip to around 55 degrees Celsius as a standard of the temperature that can be mounted on the casing are achieved. ing. However, compared with the prior art that determines the operation of clipping the CPU only by the temperature, this embodiment that determines the operation of clipping the CPU by the temperature and power consumption clearly improves the score. I can confirm. In particular, the score is improved by 5 points for 2D representing the 2D rendering processing capability and 7 points for 3D representing the 3D rendering processing capability. Further, it can be confirmed that the time during which the CPU operates at 1.60 GHz which is the maximum value of the maximum operating frequency is increased by 5%. From the above, it can be seen that the present invention is clearly superior in the effect of suppressing the degradation of the performance of the exothermic device as compared with the prior art.

  As described above, the present invention has an excellent effect of suppressing a temperature rise while suppressing a decrease in performance of a heat-generating device inside a PC. In addition, it is useful for providing a low-cost and high-performance notebook PC equipped with a video chip. Of course, the present invention is useful not only for notebook PCs but also for desktop PCs, tablet PCs, PDAs and the like having a space-saving housing. In addition to the improvement of various devices that make up the PC, it is expected that in addition to the CPU and video chip, devices that need to control the heat generation will appear in the future. Needless to say, the control method of the present invention is applicable.

  Although the present invention has been described with the specific embodiments shown in the drawings, the present invention is not limited to the embodiments shown in the drawings, and is known so far as long as the effects of the present invention are achieved. It goes without saying that any configuration can be adopted.

  It can be used for an electronic device equipped with a heat-generating device with a built-in processor.

It is an external view of a notebook PC. It is a schematic block diagram of a notebook PC. It is a block diagram which shows about the structure of the device which implement | achieves switching of the operating frequency and voltage of CPU and a video chip. It is a flowchart of the program regarding control of the emitted-heat amount. It is a flowchart of the program of "Thermal Caution Mode" regarding control of the emitted-heat amount. It is a graph which shows the change of the temperature of CPU and a video chip, and power consumption when not controlling calorific value. It is a flowchart of the program in connection with control of the emitted-heat amount of a prior art. It is a graph which shows the change of the temperature of CPU and a video chip, and power consumption when controlling the emitted-heat amount of a prior art. It is a graph which shows the change of the temperature and power consumption of CPU and a video chip when controlling the emitted-heat amount of this invention. It is a table | surface which shows a performance comparison about each case shown above.

Explanation of symbols

10 Notebook PC
13 Housing 15 CPU
25 Video chip 43 Hard disk drive (HDD)
47 Embedded Controller 53a, 53b Temperature Sensor 57 BIOS Flash ROM
61 DC-DC converter 63a, 63b Regulator 65a, 65b Sense resistor

Claims (12)

A computer equipped with a processor capable of changing the maximum power consumption value controls the amount of heat generated by the processor,
Operating the processor;
Periodically measuring the power consumption value of the processor;
Measuring a temperature value of the processor;
And a step of reducing a maximum power consumption value of the processor when a value representative of a set of the plurality of power consumption values exceeds a predetermined threshold value and the temperature value exceeds a predetermined threshold value. Control method. A computer equipped with a processor operable at any one of a plurality of maximum operating frequencies is a method for controlling the amount of heat generated by the processor,
Operating the processor at a first maximum operating frequency;
Measuring a representative value per unit time of power consumption of the processor and continuously calculating a moving average value of the representative value;
Measuring a temperature value of the processor;
Providing a frequency control set power value and a frequency control set temperature value for the processor;
When the moving average value continuously exceeds the frequency control set power value a predetermined number of times and the temperature value exceeds the frequency control set temperature value, the maximum operating frequency of the processor is set to a first maximum operating frequency. A method of controlling a calorific value, comprising a step of reducing to a lower second maximum operating frequency.   3. The method of controlling a calorific value according to claim 2, wherein the representative value per unit time is an average value obtained by sampling a current value input to the processor a predetermined number of times. Storing a temperature value of the processor when the maximum operating frequency of the processor is reduced to a second maximum operating frequency as a first temperature value;
Comparing the temperature value of the processor with the first temperature value after reducing the maximum operating frequency of the processor to a second maximum operating frequency;
3. A step of reducing the maximum operating frequency of the processor to a third maximum operating frequency lower than a second maximum operating frequency when it is determined that the temperature value of the processor is higher than the first temperature value. The calorific value control method described. Operating another processor operable at any of a plurality of maximum operating frequencies;
The method of controlling a calorific value according to claim 2, further comprising a step of reducing the maximum operating frequency of the other processor after reducing the maximum operating frequency of the processor to a limit.   The method for controlling the amount of heat generation according to claim 2, further comprising a step of shortening the unit time when the temperature value exceeds a predetermined temperature value lower than the frequency control set temperature value. Providing a frequency control release power value for the processor;
The method of controlling a calorific value according to claim 2, further comprising a step of operating the processor at the highest maximum operating frequency when the moving average value continuously falls below the frequency control release power value a predetermined number of times. A processor capable of operating at any of a plurality of maximum operating frequencies;
A frequency control unit for changing the maximum operating frequency of the processor;
A temperature sensor for measuring the temperature of the processor;
A thermal action table storing the frequency control set power value and the frequency control set temperature value is provided, and the representative value per unit time of the power consumption of the processor is measured, and the moving average value of the representative value is continuously obtained. Control that calculates and reduces the maximum operating frequency of the processor when the moving average value continuously exceeds the frequency control set power value a predetermined number of times and the temperature value exceeds the frequency control set temperature value And a computer having a part.   The computer of claim 8, wherein the processor is a video chip.   9. The computer of claim 8, wherein the temperature sensor is integrated into the processor die.   9. The cooling fan according to claim 8, further comprising a cooling fan that cools the casing of the computer, wherein the control unit controls the operation of the cooling fan independently from the maximum operating frequency of the processor based on a temperature value of the temperature sensor. Computer. An electronic component that varies in power consumption according to the information processing state and can be set for maximum power consumption;
A temperature sensor for measuring the temperature of the electronic component;
A thermal action table storing power consumption control set power values and power consumption control set temperature values is provided, and a representative value per unit time of power consumption of the electronic component is measured to obtain a moving average value of the representative values. Continuously calculating, the moving average value continuously exceeds the power consumption control set power value a predetermined number of times, and the electronic component maximum when the temperature value exceeds the power consumption control set temperature value A computer having a control unit for reducing power consumption.

Images