7970s run way cooler than 7950s... why?

[hendo420]

I currently have 3 rigs. Each has 3 cards in each. 2 rigs have 7950s and 2 rigs have 7970s.

The 7950s run on average between 74c-84c depending on the brand, sapphire runs cooler than XFX.

But my 7970s in the same environment do between 62c-67c and rarely if ever breach the 70c mark.

The sapphires (7950s & 7970s) are undervolted. The XFX cards are voltage locked so run hotter.

If I had known the 7970s ran so much cooler I would have bought them from the beginning instead of buying 7950s.

I just find it odd that a card that puts out so much more hash power can put out so much less heat. If I have the 7950 rigs in my room they try to kill me with heat. The 7970 rig is barley noticeable in my room.

Are other people seeing the same temperature difference between similar versions of the cards?

[Eastwind]

Do you run script mining?

[hendo420]

Do you run script mining?

Yes

[garumaru]

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.

[hendo420]

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.

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.

[walnutter]

I have 2 sapphire 7970 3gb vapor-x. They are quite unstable for scrypt mining. Temperatures are 70 and 63 inside computercase with side open. I don't recommend these cards for mining.

[hendo420]

I have 2 sapphire 7970 3gb vapor-x. They are quite unstable for scrypt mining. Temperatures are 70 and 63 inside computercase with side open. I don't recommend these cards for mining.

Try the firmware in this thread  https://bitcointalk.org/index.php?topic=200777.0, it makes my 7970s incredible stable(uptime at close to a week so far) at 730kh/s. I havnt tried higher clocks than what he recomends, but he showed that he got 800kh/s out of some 7970s but they weren't completely stable. I'm thinking somewhere in between is a sweet spot with like 760-780kh/s

[garumaru]

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.

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.