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I used to underclock my nVidia GeForce 8800GT by halving it's core and memory frequencies. This would make the card about 3 Celsius cooler. I would only bring it back to stock frequencies while gaming. After three years of using the 8800GT like this, it just completely broke out of the blue. This makes me question if underclocking can be dangerous without the right precautions.

I've replaced the broken 8800GT with an ATI Radeon HD 5770. I don't want to repeat what happened to my 8800GT. So here are my questions about underclocking:

  • How should core voltage be adjusted when underclocking?
  • Do core and shader clocks have to match?
  • Should core/shader drop clock in proportion to memory clock?
  • I'm using MSI Afterburner software for my new HD 5770 because RivaTuner is outdated and won't recognize new cards. MSI Afterburner doesn't allow me to edit core voltage and shader clock for some reason. If this is the case, should I not attempt to underclock my new card?

msi afterburner

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My gut reaction is to say that it wouldn't be the underclocking per se - but it might be the changing between that and normal clocking if you did it frequently. – ChrisF May 7 '11 at 21:11
@ChrisF the Intel Nahalems dial up and down their frequencies all the time with turbo boost. Graphics cards can't handle the same kind of fluctuation? I did it about once per day. This should be no worse than turning on and off the whole computer once per day, right? – JoJo May 10 '11 at 5:00
I wouldn't have thought that once per day was too much - but then I don't have much current experience with graphics cards. – ChrisF May 10 '11 at 7:57

I agree with what @ChrisF said in his comments, in addition, stuff just isn't built to last any more! In particular, I have seen so many broken Nvidia 8 series cards caused after 1-2 years, I highly doubt that 3c, over the course of 3 years made much difference.

Be happy that you managed to make it last a year longer than most people had!

As for doing this, If it really concerns you, but a cheap additional OEM case fan rather than screwing around with over/under clocking. I am sure it is safe in modern systems, but, as a personal habit, I still don't like to touch it!

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8800GT was super hot. It used only one exhaust slot, meaning hot air would recirculate in the case. My new HD 5770 is 10 Celcius lower, yet it's much more powerful. – JoJo May 10 '11 at 5:05

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