Why can't you use cool and quiet while overclocking?

[Smartazz]

I always read that using cool and quiet while overclocking an AMD CPU is generally a bad idea. Why is that the case? In case you didn't know, cool and quiet is the energy saving mode for AMD, I think Intel's is Speedstep.

 

[Bill Kunert]

Some motherboards(my Abit KN8-SLI for example) disable Cool & Quiet whenever anything except default speeds are selected. I used Cool & Quiet with an oveclocked A64 3500+ on an Asrock board with no problems. It kind of defeats the overclocking mindset to have your processor running at half speed.

 

[MarcVenice]

Well I think it's a safety precaution. Because if people turn down their multiplier, Cool & Quiet could turn it up, making your overclock unstable.

 

[Smartazz]

Originally posted by: Bill Kunert
Some motherboards(my Abit KN8-SLI for example) disable Cool & Quiet whenever anything except default speeds are selected. I used Cool & Quiet with an oveclocked A64 3500+ on an Asrock board with no problems. It kind of defeats the overclocking mindset to have your processor running at half speed.

Well it picks it up to full speed when it needs the power doesn't it?

 

[nullpointerus]

Originally posted by: MarcVenice
Well I think it's a safety precaution. Because if people turn down their multiplier, Cool & Quiet could turn it up, making your overclock unstable.

That's true. You cannot lower the CPU multiplier because when C'nQ kicks in and lowers the CPU multiplier to around 5x, the maximum multiplier will be reset to stock. So if you have a CPU with a stock multiplier of 10x and you set it to 8x when overclocking, C'nQ will raise the multiplier back up to 10x when full power is required, which effectively overclocks your already overclocked CPU.

C'nQ has a similar problem with CPU voltage. If you raise the VID (i.e. absolute CPU voltage) above stock, then C'nQ will reset it to the stock voltage levels (both at idle and load), which effectively undervolts your overclocked CPU.

One can have a stable overclock with C'nQ provided:

1. You use the stock (i.e. maximum) CPU multiplier, so C'nQ will never set it higher.
2. You use a relative voltage boost (i.e. not VID), so the voltage and clock adjustments of C'nQ will scale with each other.

Not all BIOS's provide an option for #2.

The best advice for the common/novice overclocker is just to disable C'nQ.

 

[Smartazz]

Originally posted by: nullpointerus

Originally posted by: MarcVenice
Well I think it's a safety precaution. Because if people turn down their multiplier, Cool & Quiet could turn it up, making your overclock unstable.

That's true. You cannot lower the CPU multiplier because when C'nQ kicks in and lowers the CPU multiplier to around 5x, the maximum multiplier will be reset to stock. So if you have a CPU with a stock multiplier of 10x and you set it to 8x when overclocking, C'nQ will raise the multiplier back up to 10x when full power is required, which effectively overclocks your already overclocked CPU.

C'nQ has a similar problem with CPU voltage. If you raise the VID (i.e. absolute CPU voltage) above stock, then C'nQ will reset it to the stock voltage levels (both at idle and load), which effectively undervolts your overclocked CPU.

One can have a stable overclock with C'nQ provided:

1. You use the stock (i.e. maximum) CPU multiplier, so C'nQ will never set it higher.
2. You use a relative voltage boost (i.e. not VID), so the voltage and clock adjustments of C'nQ will scale with each other.

Not all BIOS's provide an option for #2.

The best advice for the common/novice overclocker is just to disable C'nQ.

What's a relative voltage boost?

 

[aka1nas]

It looks like "overvolt by %" in the BIOS. You have to keep the multiplier and vCore at default in the BIOS to use C&Q, so this method is your only way to increase voltage and still get C&Q working. You generally will not be able to hot quite as high of an OC with it enabled. I can do 2.8Ghz on my Opty 165 w.o, and only 2.6 or so with.

 

[imported_SLIM]

I've been using c n q while overclocked for about 2 years with no problems. But as stated above you are limited to adjusting the fsb only and using % increases in cpu voltage in order to use c n q.

Alternatively, you can look into rmclock. Which does the same thing as cnq but allows you to tailor the settings as you see fit.

 

[Smartazz]

Originally posted by: SLIM
I've been using c n q while overclocked for about 2 years with no problems. But as stated above you are limited to adjusting the fsb only and using % increases in cpu voltage in order to use c n q.

Alternatively, you can look into rmclock. Which does the same thing as cnq but allows you to tailor the settings as you see fit.

I forgot about this program. Thanks.
edit: I could never figure out how to use it before, I just figured it out. Thanks.
BTW, would RMclock work for undervolting my laptop and would underclocking without undervolting lower power consumption?

 

[BlueWeasel]

Sure, I use RMC to undervolt and underclock my laptop when idle to save power.

 

[Smartazz]

Originally posted by: BlueWeasel
Sure, I use RMC to undervolt and underclock my laptop when idle to save power.

Well, my thoughts were that since I only use Word on my laptop, I can underclock it and undervolt it to save power since Word doesn't use too much processing power.

 

[BlueWeasel]

Originally posted by: Smartazz

Originally posted by: BlueWeasel
Sure, I use RMC to undervolt and underclock my laptop when idle to save power.

Well, my thoughts were that since I only use Word on my laptop, I can underclock it and undervolt it to save power since Word doesn't use too much processing power.

Exactly....RMC will work great for that.