Bitcoin Forum

I'm mining Litecoin using reaper v13 beta 4 and I only get a average of 541kH/s with my Sapphire 7970 vapor-x GHz 3GB. Here is my settings:

worksize 256
vectors 1
aggression 13
threads_per_gpu 1
sharethreads 2048
lookup_gap 2
gpu_thread_concurrency 20480

Should it not have a higher hash rate?

Damn, was planning to buy the same model and I was hoping for a better hashrate. Are you mining on Windows or Linux?

Using Windows 7 x64

you can get more but it will cost you desktop performance try changing the aggression up to 15

When changing the aggression 15 the hash rate drops to 350kH/s.

hmmm interesting then try changing GPU threads to 2

With GPU threads 2 the hash rate is 360kH/s and 35% gpu errors

Try cgminer maybe

With cgminer I get the same results.

Check out this link (assuming you're mining LTC):

https://github.com/litecoin-project/litecoin/wiki/Mining-hardware-comparison

642kh/s
--shaders 2048 --thread-concurrency 8192 -I 13 -g 2 -w 256 Card is a Gigabyte GV-R797OC-3GD, Catalyst 12.10. Wattage measured approx. with killawatt-ez. Operating temp is 72C. OC done with MSi Afterburner. GUI interaction/100% cpu lowers hashrate slightly.

580 kh/s:
@ 256 Worksize @ vectors 1 @ Aggression 13 @ threads_per_gpu 1 @ sharethreads 28 @ lookup_gap 2 @ gpu_thread_concurrency 24576, 13.1 drivers. -- Gigabyte GV-R797OC-3GD (GPU & RAM overclocked)

In the first one, thread-concurrency is way lower than yours, and it's a bit higher in the second. Share threads is way lower in the second. I haven't actually messed with any of this yet... just posting so you can look at it as a comparison.

I'm not sure what the difference is between the Gigabyte and the Sapphire or if you would be able to safely use the same settings, you would probably have to research it to compare. Are you overclocking? Also what drivers are you using? Looks like 12.1 and 13.1 are being used above. For whatever reason, I've heard that some drivers work better than others depending on the chipset.

It looks like this guy was able to get it above 500 kh/s by overclocking the memory to 1680mhz:

https://bitcointalk.org/index.php?topic=168990.0

Also, note that he was using reaper.

The Sapphire 7970 standard edition with Vapor X gets 650k/H per second out of the box. But why does my GHZ edition barely do 500 kH/s?
 

I would really like to know this as well. I have the cards performing at 595 Kh/s after a few hours of fine tuning but they are really sensitive to any changes. Changing to any aggression except 13 throws the cards back to around 400 Kh/s, or lower.

Can you post what you did please. 595kH/s would be better than 500kH/s for me.

The hash difference is likely to be the Core clock and Memory clock speeds. Post what yours are set up at because those flags that have been posted are under the assumption you've overclocked which is rather normal to get above 600khash/s.

The core is
The Core clocks speed 1050MHz and Memory clock speed 1500MHz of the Sapphire 7970 vapor-x GHz.

Try changing the core and memory clock settings to the non-ghz version, then find an aggression profile for the non-ghz. The GHz is just a card that was over clocked at the factory because it was more stable than others over clocked.

You will need to do a rather unsafe overclock on memory. I have core voltage at 1080 (default 1200) with the core clock set at 856 mhz (performance drop at 857 or higher). Then tuned the memory voltage between 1625 to 1630 (default 1500). When the memory is overvolted you can turn up the memory clock to 1775-1785 mhz. Be sure to run Intensity at 13 in cgminer. If you set any other intensity with these settings it drops 100 kh/s per gpu. I believe these ghz editon gpu's are going back to the store in my case as they are horrible for scrypt mining.
The speeds seems to be exactly same with 1333mhz, and 1600mhz RAM. Please PM me if you can find any settings that perform better. Hope this helps.

Will have a look thanks.

hmm I cannot even change mem voltage on my sapphire ghz 7970, does any of you have the same problem?
I am getting like 300+ kh scrypt hash rate no matter what I do, this really sucks!

What software are you attempting to use to change the memory voltage? MSI Afterburner works for me with a Sapphire 7970 Dual-X. There will be a drop-down type arrow right next to the core voltage control that you can click on and it will reveal the memory voltage control.

As for your hash rate, try these settings in cgminer:

That gets me ~690Kh/s @1019mhz core and 1496mhz memory (core voltage set to 1100mV, mem voltage 1500mV).