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Runtime Power Management

v1.0

Introduction   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

What is EIST?  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
What is Cool’n’Quiet   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Why are EIST and Cool’n’Quiet needed? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
What are the required components for EIST and Cool’n’Quiet to function? . . . . . . . . . . . . . .2
How will EIST and Cool’n’Quiet impact HP Customers?  . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Advantages of using EIST/Cool’n’Quiet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Disadvantages of using EIST/Cool’n’Quiet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Known Issues  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Resources for EIST and Cool’n’Quiet  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Frequently Asked Questions  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Summary of Contents for dc5100 - Microtower PC

Page 1: ...n Quiet needed 2 What are the required components for EIST and Cool n Quiet to function 2 How will EIST and Cool n Quiet impact HP Customers 8 Advantages of using EIST Cool n Quiet 9 Disadvantages of using EIST Cool n Quiet 9 Known Issues 9 Resources for EIST and Cool n Quiet 10 Frequently Asked Questions 10 ...

Page 2: ...processor power management technology This processor fea ture dynamically adjusts the operating frequency and voltage of a processor up to 30 times per second depending on the CPU load When full processor performance is not needed the processor slows its fre quency resulting in significant power savings which results in cooler and quieter performance While Cool n Quiet technology is new to desktop...

Page 3: ...nd 945 based systems This option is located in F10 Setup in the Power OS Power Management sec tion The default EIST BIOS support setting depends on several factors Thermal Monitor 2 TM2 is an older Intel processor feature that allows CPU throttling to slow down the processor EIST will replace TM2 Some older processors support TM2 but do not support EIST while even older processors do not support e...

Page 4: ...m BIOS The kernel power policy manager sets the rules for using the correct performance state at a given time Once the performance state is determined Windows uses the proces sor driver or system BIOS to make the changes The processor driver changes the performance state if the processor is not Hyper Threaded HT The system BIOS changes the performance state if the processor is HT enabled The use o...

Page 5: ...nt scheme is adaptive If a power management scheme has not been modified it will have the default processor performance control policy However a modified power scheme will not pro vide external notification regarding its current control policy To verify processor performance control policy perform the following steps 1 Click Start Run 2 Type CMD 3 Type powercfg query The system displays the curren...

Page 6: ...6 Home Office Desk in default state Home Office Desk in adaptive state ...

Page 7: ...ystem 3 4 GHz under throttled condi tions with EIST both enabled and disabled Maximum Processor Speed You can check the maximum speed setting for systems with EIST or Cool n Quiet enabled by performing the following steps 1 Click Start All Programs Accessories System Tools System Information 2 Locate the Processor listing The maximum speed of the processor listed in MHz displays in the right pane ...

Page 8: ...mpatibility These tests include Applications bundled with HP bPC computers Operating system images bundled with HP bPC computers Peripheral drivers bundled with HP bPC computers Samples of popular applications and games By default the Home Office Desk power scheme that is shipped with the HP image is non adaptive This means that under normal circumstances a system will not see any power saving ben...

Page 9: ...DR i915 systems 786C1 v2 14 or later HP BIOS for DDR2 i915 systems 786C2 v1 06 or later Windows XP Service Pack 2 Windows Server 2003 Service Pack 1 Systems running Windows XP Service Pack 2 with older Intel processors that only support TM2 do not provide RTPM capability Windows XP Service Pack 2 supports RTPM for only EIST processors Windows XP may report inaccurate processor speed For more infor...

Page 10: ...mal affect on processor pricing Q What will the lower power do to the performance of my system A The lower power consumption has no affect on perceived system performance While the system does operate at a reduced speed it only does so for applications that require lesser speeds so the actual performance of these applications is not affected You will not see a performance drop since the processor ...

Page 11: ...mance worsens after a significant amount of time the chances of a relation to EIST is low Testing has indicated no noticeable performance degradation copyright 2005 Hewlett Packard Development Company L P The information contained herein is subject to change without notice The only warranties for HP products and services are set forth in the express warranty statements accompanying such products a...

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