Quote from: hendo420 on September 11, 2013, 05:59:08 PM

Quote from: garumaru on September 11, 2013, 05:35:38 PM

Brands of 7970? It could be that your 7970s have better heatsink design.
I don't recommend XFX cards for mining because their heatsink design overheats the GPU.
I've tried PowerColor, Sapphire, Gigabyte, XFX, AMD and MSI.
Sapphire and MSI TFIII tend to be the best performing overall.

I have 3x sapphire 7950s and 2x sapphire 7970s and a gigabyte 7970. All 7970s have same bios regardless of brand, it nets me the most hash speed and unlocks the voltage. Cheesy

But I would expect the sapphires, either 7950 or 7970 to have nearly the same heatsink, they look almost identical except for the plastic shroud is a bit different.

At first I thought maybe it was because the 7970s run with -g 2 -i 13 while the 7950s run -g1 -i 19 but I changed the 7950s to the -g 2 -i 13 and tweaked the hell out of it trying to get back up to a normal hash speed. It maxed out at 550kh/s each card instead of 680kh/s and ran just as hot.

Has anyone tried flashing the 7950s with 7970 firmware? Maybe if I used my sapphire 7970 firmware on them that works so well on most 7970s it would be cooler and hash just as fast.

Oh and try to switch around cards in your rigs.

I have 2 rigs, originally one rig I had 4 x 7970, on the other I had 4 x 7950. One of 7970 would always hit close 85C whereas the rest would be in 70 range. Same thing with 7950 rig. One card would always have higher temperature than the others

One day just for the hell of it, I decided to switch out those 2 cards with high temps. With a great mystery, they perform at a similar temperature range as the rest of cards. Of course I am using the same settings.