Sapphire 11197-03-40G (7970) - need help optimizing for LTC mining

[Martok88]

I've got 2 of these cards so far, each hitting ~580 Kh/s with stock settings.
I'm trying to overclock the memory and core for better rates, however they become unstable at about 1575 MHz memory clock, which seems pretty low.
This could have something to do with the "boost" feature, but I'm not really sure.
I'd really appreciate it if someone could point me in the right direction to get higher memory speeds.

[pekv2]

Give this a read.

Consolidated Litecoin Mining Guide for 5xxx, 6xxx, and 7xxx GPUs

[Martok88]

Give this a read.

Consolidated Litecoin Mining Guide for 5xxx, 6xxx, and 7xxx GPUs

Thanks. I had read the guide before, but found someone's settings in the thread that pushed my cards up to ~635 Kh/s  (1044 core, 1500 mem)
I'm still hoping for 700+ though, if anyone has any further advice.

ckolivas was able to get the memory clock up to 1900 stable: https://bitcointalk.org/index.php?topic=28402.msg1635964#msg1635964

[Marrs]

I get 700khs at 1024/1692, 8192 tc, 2 gpu threads, 13 intensity.

That specific ratio of core to memory seems to be the sweet spot for my sapphire 7970. I raised my memory as high as I could while keeping the system stable, then set the core using that ratio.

[Martok88]

I get 700khs at 1024/1692, 8192 tc, 2 gpu threads, 13 intensity.

That specific ratio of core to memory seems to be the sweet spot for my sapphire 7970. I raised my memory as high as I could while keeping the system stable, then set the core using that ratio.

Thanks for the input. Do you have the exact same card, and what software did you use to OC?

[Marrs]

I get 700khs at 1024/1692, 8192 tc, 2 gpu threads, 13 intensity.

That specific ratio of core to memory seems to be the sweet spot for my sapphire 7970. I raised my memory as high as I could while keeping the system stable, then set the core using that ratio.

Thanks for the input. Do you have the exact same card, and what software did you use to OC?

Yes, I have that card exactly. I just use the core and memclock parameters (and power boost for stability) with cgminer.

[Martok88]

I get 700khs at 1024/1692, 8192 tc, 2 gpu threads, 13 intensity.

That specific ratio of core to memory seems to be the sweet spot for my sapphire 7970. I raised my memory as high as I could while keeping the system stable, then set the core using that ratio.

Thanks for the input. Do you have the exact same card, and what software did you use to OC?

Yes, I have that card exactly. I just use the core and memclock parameters (and power boost for stability) with cgminer.

Maybe the power boost is what I'm missing. What did you set yours to?

[Marrs]

My final settings are: --gpu-powertune 20 --gpu-fan 0-100 --gpu-engine 1024 --gpu-memclock 1692 -I 13 -w 256 --thread-concurrency 8192 -g 2

Your card may not overclock the same as mine. You might be able to go higher, or not as high.

[Frizz23]

I've got 2 of these cards so far, each hitting ~580 Kh/s with stock settings.

I have tried lots of Sapphire 7970 cards (Vapor-X, OC, GHz Edition, 3 and 6GB versions, etc. ...), but the best one for LTC mining is the bog-standard Sapphire 7970. It does 680 Kh/s with no overclocking.

No idea why the other, much more expensive (and supposedly faster), Sapphire 7970s cards are much slower mining LTC.

[frediiii]

[...] the best one for LTC mining is the bog-standard Sapphire 7970. It does 680 Kh/s with no overclocking.

No idea why the other, much more expensive (and supposedly faster), Sapphire 7970s cards are much slower mining LTC.

I second that. I have a standard sapphire running at 688.8 Kh/s average with stock settings. it's Club3d 7970 neighbor pulls 652 Kh/s stock.