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Well, I have a Gigabyte Radeon 7950 on a fresh W7 Ent 64bit install, 13.1 drivers, GUIMiner Scrypt. Seems normal, right? Well, here's the problem.

I can only mine on the 7950 Low Usage setting.

I can increase the intensity but IF I increase the thread concurrency, it will not connect. This occurs for both CGMiner and Reaper. But for reaper, increasing the intensity above 13 causes mostly stale shares.

I still get around 350 Khs, but I should be getting much more obviously. Anybody else ever experience this? I have no ideas what to do.

Essentially, if I do not mine on low usage, it will not connect which makes no sense.

Thank you in advance!

I've been running sapphire 7950. tested share output with variety of settings and the ones that seem to perform well and stable are: 13.3 beta driver, gui miner 7950 high setting - cgminer program. It steadily runs at 530 Khs

I can get it to run higher, but the drivers crash...recover and overall lose share output

13.1 Beta or did you mean the 13.3 Beta?

13.1 is an official release. The settings you mentioned do not work on my current config. Anything above the Low Settings (sans just intensity for CG, don't work).

yes, 13.3 . edited

Also, I modified core and memory setting and settled on 925 / 5000. I get higher Khs output with OC, but share output is minimally higher over 1 hour test span making it not worth it.

I'll give it a shot. Hopefully it will work.

One thing I just learned tonight is you need to set powertune to +20% to in effect turn it off. Otherwise it'll drop your clock speed on and off to reduce power usage. Just a tip.

Does that run stable for you with what output ?

Unfortunately the 13.3 drivers yield the same results.  :-\

I have one of the MSi twinfrozr 7950s, I'm able to run it at 1000 core/1500 mem(well 6000 effective) at 1031 VDDC
Guiminer with cgminer.  Thread concurrency 24000, intensity 20 gets me 580ish khash

Not sure if this will help you much, but here are my settings with a 7950:

GPU clock: 975MHz (via Sapphire TRIXX)
GPU RAM:  1500MHz
GPU Voltage: 1.093V
PowerTune: +20%

I run Reaper 13v4, with the following config file:

reaper.conf:

litecoin.conf:

The system is basically unusable while mining, and periodically at startup it will crash the AMD driver, but once it's running okay for 10 seconds or so it will keep running all night. Right now, it pulls around 575kHash/s. I've heard of people doing better, but for my purposes I'm happy -- and GPU temps top out around 77C.

Start out with stock clocks then slowly bump the core and mem clocks upward.  I found that just boosting to the highest value (at least on the 5000 series) yielded kinda low hash rates.  Another tip would be to start with a lowish thread concurrency and high intensity/agression (17-18), then move the thread concurrency up by 1000 or so each time you try it.

Yes seems to run great. Been getting about 530K/s at I 17 for ltc, I'm overclocked some on engine and memory. Would have to get home to check exact figures. Powertune saves power by dynamically lowering clock speed, nothing to do with voltages, as far as I can tell. Ltc farming can get a huge boost from overclocking memory moreso than gpu, it seems for me.

I run three 7850's by Sapphire, the two fan model, with the following settings, and pull 595-600 KH/s, per card - about 76 C on each card:

Using CGMiner & MSI Afterburner to overclock

Stock Voltage
CPU: 1000
MEM: 1525
Power: 10%
Intensity: 20
worksize 256
-g 1 -v 1
lookup_gap 2
thread_concurrency 21712

They run stable as long as they are headless (no monitor), and I'm not trying to use them for anything else.

I've been a bit scared to go as high as 1525 but maybe I should try it when my new power supply arrives.. :)

How much system RAM do you have? Any less than 4GB might your problem.

Thanks roy7 for that tip! Setting powertune +20% just increased the hashrates on my 7950s from 600 kh/s to 640 kh/s. I could had sworn that I read powertune was only applicable to 69xx cards.

Can you confirm that you are running 7850's not 7950's? The mining hardware comparison of 7850's seems to suggest that 400 kh/s is around the highest it can hash at - if it can do 600 kh/s then it would be much better deal than a 7950 since they are half the price...

http://www.newegg.com/Product/Product.aspx?Item=N82E16814202004

A shoot, very sorry I mistyped - I meant 7950s :-P

I got a Gigabyte 7950 and got it running around 650-660 khash/s with Core clock to 1076 and memory clock to 1495.

Thread Concurency: 20480
Intensity 20
threads_per_gpu 1
worksize 256

ThreadConcurency over 8192 seem to require a lot of ram(around 1.5Gb per card) maybe it is your problem ?

With guiminer - CG miner

I'm getting 629hash with the default settings built into the software. (drop down menu)

7950 Gigabyte

Open terminal and enter setx GPU_MAX_ALLOC_PERCENT 100; this should allow you to move your thread concurrency and intensity up without any problems