280gtx underclocking

[JonJ678]

Hello all. I have a 280 that runs very hot, i wish to change the speed at which it is running to cool it down. However I do not wish to cripple it with folding at home.

Now, I believe the shader clock rate directly affects folding ppd, and memory speed has no impact. Does the core speed have an affect?

I am currently wondering if I can underclock the core and memory, and overclock the shaders with a net increase in ppd and a decrease in temperatures.


Thoughts?

 

[shadowscotland]

core has some effect but dropping the core and upping the shaders acheives massive ppd boost and a drop in temps. your need to swap it back if you game so rivatuner would be a better bet than a re-flash

 

[JonJ678]

Well, it appears the temperature differences are not very big. The difference between 500mhz core and 650mhz seems to be three degrees, slowing memory down to 900mhz lowers temperature by perhaps two degrees. The shader speed is just about happy at 1500, but increasing it to this brings temperature up by about the same amount that dropping the other two lowers it.

I tried lowering core voltage (via evga), and even a very small decrease in voltage with a large decrease in core speed leads to instability. I'm not convinced I trust the software voltage change though. Apparently linux can overclock graphics cards in software, I shall continue testing