Windows 7: Underclocking Intel i5 750

I have an Intel i5 750 CPU running on Gigabyte P55A-UD3R mainboard on my system. The weather is very hot here, I don't need much CPU speed these days and CPU fan was making too much noise. So I underclocked my CPU by decreasing its multiplier from
133 x 20 = 2.66 GHz
to
133 x 9 = 1.20 GHz.

And also decreased some voltage values. I don't know much about overclocking and underclocking, therefore I can't make sure whether I applied the optimum settings or any more optimization should be applied.

My BIOS screenshots are as below:

Main Screen


M.I.T. Current Status


Advanced Frequency Settings


Advanced Memory Settings


Advanced Voltage Settings


Miscellaneous Settings

(What are these settings for?)


Is this configuration OK? My main concern is the memory frequency. Since I decreased the CPU speed, I think I should decrease the memory speed as well, isn't it so? What about the voltage settings? Should I further decrease any voltage value?



My system is running very good at the moment. I have no problem. I just want to make optimization, and decrease power consumption.

Any help will be appreciated.

Wow, to me this is odd. When idling, if you have turbo on, your multiplier will drop to x9. It will only go to x 21 when it is needed. Are you saying you disabled turbo, and manually set the multi to x9 all the time?

In any case, your BCLK is still 137.07 MHz (stock is 133MHz). Since the Ram runs it own multiplier x the BCLK, if you haven't changed the memory multiplier, then the momory speed hasn't changed. You have no reason to lower the memory speed, and the voltages should remain unchanged as well. I think you are good to go with the settings you have, if that's what you want to do...

I do believe the temperature decrease will not outweigh the loss of performance you will experience. What kind of temps were you running?

A Guy

If you refer to the 2nd screenshot, both turbo and non-turbo multipliers are x9.
This much of a multiplier decrement may seem odd, but I'm not using CPU power these days. All I'm doing is office work and watching movie at nights. When I start playing games again, I will restore the normal settings back.

I was wondering what BCLK is, I made a quick search now but still didn't understand completely. Should I change BCLK to 133MHz?

Core temperatures are listed in the 2nd screenshot. I also turned off the case fan, it is very quite at the moment.

Wouldn't it be much easier and accomplish the same thing to leave everything a default settings and if disabled, enable Speedstep and let it handle it?

Processors — Frequently asked questions for Enhanced Intel SpeedStep® Technology on Mobile

Don't worry about the slight difference, yours is just a tad over, this is normal. BCLK is the frequency that the CPU and Ram run at. You then have different (and separate) multipliers for each. IE: your current CPU multiplier is x9, hence 133MHz x 9 = 1.197GHz.

A Guy