Undervolting CPU for cooler temps!

What happens when you UNDER volt your CPU?

The Northwood is rated as 1.525 to 1.6 volts operating range. Mine runs fine so far at 1.33 volts. The temps have dropped dramatically due to the voltage drop.

My new p4 830 D is also running at 1.2 volts now but it is rated as 1.25 minimum. Again the temps are way down.

Prime runs fine on both so far.

Do you think it's safe to continue the undervolting? Why is the minimum voltage so much higher than the chip appears able to run at?

Their Specified voltage is actually an Average/ median.

The chips are able to actually handle higher voltages and are designed to be able to run at less than the stock voltage.

To ensure the chip does it's calculation correctly 99.9% of the time they use the median.

Tebore said:

To ensure the chip does it's calculation correctly 99.9% of the time they use the median.

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So the chip might fail at some point to operate properly? Is there anyway to know when a failure has occured....besides the obvious blue screen of death?

orion456 said:

So the chip might fail at some point to operate properly? Is there anyway to know when a failure has occured....besides the obvious blue screen of death?

Click to expand...

It *could* error, or mispredict, but most chips will run lower. The reason they use median as was pointed out, is because every chip is a little different, and they want to be sure than the end user doesn't get one that runs on the high side and uses a lower voltage. The only way to tell what a particular CPU does is to try and test.

There are two ways to reduce temps. One is to increase cooling efficiency by using a better cooling and the other is to reduce voltage. I like increasing cooling better, because I'm one that likes max performance, and to increase the FSB to max, you have to raise the voltage.

Of course, increasing cooling can get expensive depending on how high you want to go. If you go phase, you can raise it higher than water, if you go water you can raise it higher than air, but each one of those is much more expensive as you go up in cooling ability.

Right now, I am on air, with moderate voltage, but in the future I plan on going to phase change. It costs alot of money, but the increases in performance are very high.

It depends on the person, and what they are using the system for, and how much they want to spend really. It also has alot to do with what kinds of risks you are willing to take.

orion456 said:

So the chip might fail at some point to operate properly? Is there anyway to know when a failure has occured....besides the obvious blue screen of death?

Click to expand...

When I say they use the median to get 99.9% operation is because nothing in life is 100%. But if used under their designed conditions it'll be more than enough for the normal end user.

But as with anything you can always push the limits. No harm in under volting it but it's your job to ensure it doesn't error not intel's.

Tebore said:

but it's your job to ensure it doesn't error not intel's.

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Ah yes....and how does one do that?

orion456 said:

Tebore said:

but it's your job to ensure it doesn't error not intel's.

Click to expand...

Ah yes....and how does one do that?

Click to expand...

Stress testing comes to mind...

Strat