Daily performance on throttling cpu

perdomot

Golden Member
Dec 7, 2004
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Just built myself a new i5-4590 rig and was wondering how letting Win bring the cpu frequency down to 700mhz from the default 3.3Ghz would affect performance on daily tasks like web browsing, video viewing(online & offline), etc. I know it can jump up as needed depending on the task but has anyone ever benched a cpu to compare states performance? Haven't seen any charts showing if there is a difference. Thanks.
 

sm625

Diamond Member
May 6, 2011
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You can test it yourself with a very simple batch file:

Code:
powercfg.exe -setacvalueindex SCHEME_BALANCED SUB_PROCESSOR PROCTHROTTLEMAX [B]10[/B]
powercfg.exe -setactive SCHEME_CURRENT

Just set your power plan to balanced, and set the bolded number above to any number 0-100. I have a couple batch files on my desktop that switch from 10, 50, and 100 pct. You will notice a lag at 10% but everything still works fairly normally.
 

Jovec

Senior member
Feb 24, 2008
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You won't notice any performance hit from proper SpeedStep frequency scaling.

You would notice if the CPU frequency was permanently scaled down.
 

coercitiv

Diamond Member
Jan 24, 2014
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Just built myself a new i5-4590 rig and was wondering how letting Win bring the cpu frequency down to 700mhz from the default 3.3Ghz would affect performance on daily tasks like web browsing, video viewing(online & offline), etc.
You won't notice any difference as long as you configure this on the Balanced or High Performance power profiles. On Power saver profile you might notice some stutters under certain scenarios. However, you won't notice much improvements on the power usage front either. Most of the power savings are already done through sleep states - cores power down when idle anyway.

As a funny side note, I work on laptops only, and both my units are configured to not drop clocks bellow base speed when plugged in. Idle power usage increase is negligible.
 

perdomot

Golden Member
Dec 7, 2004
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You won't notice any difference as long as you configure this on the Balanced or High Performance power profiles. On Power saver profile you might notice some stutters under certain scenarios. However, you won't notice much improvements on the power usage front either. Most of the power savings are already done through sleep states - cores power down when idle anyway.

As a funny side note, I work on laptops only, and both my units are configured to not drop clocks bellow base speed when plugged in. Idle power usage increase is negligible.

Thanks for the feedback. I set it to 50% minimum cpu and temps/volts appear to stay the same.
 

escrow4

Diamond Member
Feb 4, 2013
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Zero. My 4770 non K runs mostly at 800MHz or the next step up - 1.4Ghz or something.
 

Jovec

Senior member
Feb 24, 2008
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it works great. why do we need both CnQ and this? I love C1E it's incredible

I'd guess it's a holdover from when C1E wasn't a thing yet - easier to drop clocks and volts than to shut off nearly all power to a core. It probably still provides some benefit on mobile too, where every little bit helps. But otherwise, the vast majority of idle power savings comes from C1E.
 

Yuriman

Diamond Member
Jun 25, 2004
5,530
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Thanks for the feedback. I set it to 50% minimum cpu and temps/volts appear to stay the same.

I'd leave it alone. There's virtually zero performance hit and it both saves you electricity and extends the life of your components, allowing it to clock down fully at idle.
 

VirtualLarry

No Lifer
Aug 25, 2001
56,587
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Title in OP is wrong. "Throttling", is a reduction in max CPU performance, due to power or temp limits. "Speedstepping" is when the CPU clocks down in frequency / voltage, to save power, but can clock back up under load conditions.
 

BonzaiDuck

Lifer
Jun 30, 2004
16,627
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I don't understand why anyone would want to fiddle with the default EIST/C1E idle speed. I can sit here all day long, and watch the voltage fluctuations on my OC'd K processors. They bounce around a bit, mostly between 0.98V and 1.2+. Leave it on HW Monitor, it will trap the maximum turbo voltage when the processor occasionally ramps up to 4.7 on most cores. I figure the power consumption is mostly determine by the ~1.0V average.

The Haswells use less power. Why fret about it?