I tried messing with AMD Gpu Tol and CCC profiles but I finally gave up and just modded bios. As far as I was able to test by using Furmark on otherwise clean system (Vista 64) there is no change with temps after crossing 1.3V so I suppose that is max voltage as set via bios. And I won't mess with hardmod (well maybe pencil mod
).
Now here is how I set frequency/voltage and fan settings:
Fan ramp on is very steep and when testing in Furmark the fan hovers between 65-80%. So it's not quiet but it definitely is cool. Bios modding brings with it another can of worms as every change in memory frequency results in flickering of the screen. The target for my bios modding was to maximize power saving and also maximize speed in 3D. Memory in 4870 is quite power hungry, setting it to 300mhz in place of 900mhz (not my measurement) gets you around 20-30W. I can live with occasional flicker as it doesn't happen when playing games (gpu stays in High Power 3D). But some users reported that playing movies sometimes has gpu changing from Low Power 3D to High Power 3D and so flickering. The only time it happens for me is when I start BluRay movie (hardware decompression) but only first few seconds of the movie. From the GPU-Z I see that after few changes between 2d, lp 3d and hp 3d it stabilizes at 3d with occasional "trips" to lp 3d. Since I have the same memory settings for both, there is no flickering.