Run at 100% speed all the time?

Oct 26, 2005
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#1
I'm not talking about 100% load, but rather running at 100% clock speed for CPU, etc. Disabling all power management. I've just been thinking about it for a while and am curious to run a few benchmarks to see how power gating and throttling impact real world performance. It's been many years since we've implemented all these power saving measures and we just accept it as SOP now, but I'm curious if anything has been lost?

Other than BIOS settings and Windows Power Settings, is there anything else that I could use to force the system to run at 100% speed at all times?
 

coercitiv

Diamond Member
Jan 24, 2014
3,187
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#3
Disabling all power management optimizations might actually hurt performance, at least in power bound scenarios.

From VMware performance best practices:
Availability of the C1E halt state typically provides a reduction in power consumption with little or no impact on performance. When “Turbo Boost” is enabled, the availability of C1E can sometimes even increase the performance of certain single-threaded workloads. We therefore recommend that you enable C1E in BIOS. However, for a very few workloads that are highly sensitive to I/O latency, especially those with low CPU utilization, C1E can reduce performance. In these cases, you might obtain better performance by disabling C1E in BIOS, if that option is available.

C-states deeper than C1/C1E (i.e., C3, C6) allow further power savings, though with an increased chance of performance impacts. We recommend, however, that you enable all C-states in BIOS, then use ESXi host power management to control their use.
 

nerp

Diamond Member
Dec 31, 2005
9,805
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#4
Not worth messing with.
 
Feb 25, 2011
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#5
I did it the other way around and disabled Turbo Boost on my laptop.

I somehow installed enough background apps that the CPU was stuck in turbo mode all the gorram time, even though it was at <2% load. Disabling Turbo keeps things running cool and quiet, and gives me an extra hour or so of battery life.
 
May 28, 2012
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#6
SSD benchmarks tend to show the greatest difference when various C States are enabled. I think this is because the benchmark does not load the CPU enough to force it to run at full speed. Real world applications should show less difference because they will be using the CPU more.

You can use ThrottleStop to monitor what C States your CPU is using when idle. It supports many of Intel's newer CPUs.

ThrottleStop 8.00
https://www.sendspace.com/file/of4xwj
 

moonbogg

Diamond Member
Jan 8, 2011
9,751
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#7
You can just go to power management and set CPU min speed to 100%. I like the throttling though. I don't want full voltage and full speed when all I'm doing is watching por..uh..reading stuff.
 
Aug 25, 2001
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#8
If you do a non-K SKL BCLK OC, then the C-states and SpeedStep and stuff are all disabled, so the CPU runs at max clocks all the time. At least, that's been my experience with Windows 7 64-bit and my ASRock "SKY OC".
 

Flapdrol1337

Golden Member
May 21, 2014
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#9
windows powerplan to high performance should do that already right?

Could disable all powersaving in the bios too.
 

ninaholic37

Golden Member
Apr 13, 2012
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#10
A Pentium II or lower should do this automatically, or anything under MS-DOS.
 

Dufus

Senior member
Sep 20, 2010
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#11
Could disable all powersaving in the bios too.
BIOS can not disable all power saving idle states. Has to be done from Windows and can be done regardless of BIOS settings.
 

nerp

Diamond Member
Dec 31, 2005
9,805
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#12
If you do a non-K SKL BCLK OC, then the C-states and SpeedStep and stuff are all disabled, so the CPU runs at max clocks all the time. At least, that's been my experience with Windows 7 64-bit and my ASRock "SKY OC".
Back in my overclocking days this was totally true. I'm sure it still stands. OC means turn off speedstep/cool'n'quiet or whatever.
 

coercitiv

Diamond Member
Jan 24, 2014
3,187
468
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#13
SSD benchmarks tend to show the greatest difference when various C States are enabled. I think this is because the benchmark does not load the CPU enough to force it to run at full speed. Real world applications should show less difference because they will be using the CPU more.
Although this is true I would like to add a few observations:

1. Really big differences were observed on older platforms (C2D and likely some of the followers). Those actually required special tweaks in power management at OS level, some of which weren't even readily available to normal users. Nowadays all a user needs to do is set Windows power profile to High Performance and this will give 90% of the performance benefit for a few easy clicks.

2. CPU operating frequency has a big impact on SSD benchmarks, even with proper C states enabled. This is very important since CPU frequency has less of an impact on power consumption than C states when considering idle cores. Again, leaving C states in place but keeping the CPU at max operating frequency should give the best out of both worlds - very good performance with minimum power consumption penalty.

3. Throttlestop is great at maximizing the performance/power ratio on mobile systems. From keeping the CPU at max turbo frequency even in idle, to power management customization and slight undervolts, this tool is a must for mobile power users who want to squeeze performance out of their systems. Many thanks to the developer, especially now when his tool is effectively surpassing Intel Extreme Tuning Utility in functionality.
 
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