Cool'N'Quiet

Icepick

Diamond Member
Nov 1, 2004
3,663
4
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It's an AMD feature to reduce noise in your system. When the CPU is at idle the motherboard will dynamically lower the processor speed by decreasing the multiplier. When the processor runs slower it will, in theory, run cooler. When the motherboard detects the CPU is cooler it will lower the fan speed and as a result noise from the fan will be reduced. Hence Cool and Quiet.

When a CPU intensive application is fired up, like Doom3 or Half Life 2, the motherboard will raise the multiplier back to it's peak setting (for my 3500+ that's 11) to make the CPU run fast enough to adequately run the game. When you shut down the game, the multiplier gets lowered again to throttle your CPU.

In my experience, the multiplier will change from 11 to 5 at idle which causes the CPU to run at 1GHz instead of 2.2.

Anyone else feel free to correct me if I'm wrong, but that is my understanding.
 

tallman45

Golden Member
May 27, 2003
1,463
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Icepik,

Sounds right, my 3500+ on a A8V clocks down to 1.0 Ghz during Cool and Quiet mode. The info panel shows voltage as 1.045 as well.

 

lockmac

Senior member
Dec 5, 2004
603
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0
Is the change in speed that Cool n' Quiet enforces going to affect my system much? Like, how instant is it when it raising the multiplier to increase the speed? Say, if I was to turn off Cool n' Quiet, would I notice any speed difference?

Cheers
 

Engineer

Elite Member
Oct 9, 1999
39,230
701
126
Originally posted by: lockmac
Is the change in speed that Cool n' Quiet enforces going to affect my system much? Like, how instant is it when it raising the multiplier to increase the speed? Say, if I was to turn off Cool n' Quiet, would I notice any speed difference?

Cheers


I don't notice any speed difference. Also note that Cool 'n' Quiet does not lower your fan speed, only your CPU speed (and voltage?). You'll need a thermally controlled fan/hs or an option such as Asus Q-fan (varies fan speed based on temperature - BIOS function of ASUS boards). Using Cool'n'Quiet alone, my A64 3200+ runs around 28C at idle (Panaflo 80mm L1A fan on the Venus 7+ heatsink). When used with Q-fan, the Panaflo will kick on when the temperature is around 52C and back off in the 30's. The fan will actually go off for up to 10 minutes at a time and is barely audible when it is on.

Speed ramps up nice and quick when needed. My A64 and Sonata along with Cool'n'Quiet and Q-fan = one dasm quiet system.