Hi Bazzip.
I have just setup 2 7950s on windows & also had a few trials getting the performance right.
This is what worked for me....
1. Take those 2 "setx" commands out of you .bat file & run them in a new CMD window. ( START > SEARCH > CMD). You only need to do this once. My understanding is that setx permanently sets the value in Windows, but doesn't affect the window it is run in.
2. Reboot. If the Graphics Drivers crashes, CGMiner should run, but performance won't be as good. In my experience. I found best results always after a Reboot... Even when I was just experimenting alot with th OC settings... If performance seems poor, try rebooting then starting CGMiner without making any other changes.
3. Move your CGMiner .bat parameters into a config file. cgminer.conf in the CGMiner folder. Below is a copy of mine which works good for me.
4. Try a few lower values for Thread-Concurrency. For my setup, anything over 14336 (8x1792) causes hardware errors.
Just these few changes here got me a good improvement. While Kh/s went down a little, the Utility Rate & Accepted shares more than doubled, & HW errors stopped.
5. Adjusting the clock speeds increased hash rate about 15kh/s each.
My setup performs best with: Core Clock = Memory Clock * .67 ( 1450*.67=971 )
You should experiment with the Core:Memory Clock ratio. Just remember to reboot if anything crashes.
There is a good guide at
https://bitcointalk.org/index.php?topic=175646.0I currently get 580kh/s on each card, with a Utility Rate of about 35%.
Before i was getting 640Kh/s each, with a Utility Rate of 8%... About the same as you are getting now.
I also noticed better performance in some pools than others...Coinotron.com was one of the poorer ones for me. I get a much better result with give-me-ltc.com
So you might want to compare a few.
Hope this helps.
my cgminer.conf
============
{
"pools" : [
{
"url" : "
http://127.0.0.1:9332",
"user" : "WorkerUsername",
"pass" : "WorkerPassword"
},
{
"url" : "stratum+tcp://stratum.give-me-ltc.com:3333",
"user" : "WorkerUsername",
"pass" : "WorkerPassword"
}
],
"kernel" : "scrypt,scrypt",
"scrypt" : true,
"no-submit-stale" : true,
"temp-overheat" : "80,80",
"temp-cutoff" : "90,90",
"temp-target" : "70,70",
"api-port" : "4028",
"api-listen" : true,
"api-allow" : "W:127.0.0.1",
"intensity" : "20,20",
"vectors" : "1,1",
"worksize" : "256,256",
"gpu-fan" : "auto,auto",
"gpu-powertune" : "20,20",
"thread-concurrency" : "14336,14336",
"gpu-threads" : "1",
"expiry" : "120",
"no-pool-disable" : true,
"log" : "5",
"shares" : "0",
"queue" : "1",
"scan-time" : "60",
"temp-hysteresis" : "3",
"kernel-path" : "/usr/local/bin"
}
After 3 minutes (same as your screendump) with these settings I'm getting this, which looks about normal for me:
1.196Mh/s (avg) Kh/s from the 2 x 7950s
126 Accepted (give me ltc pool) - 0 HW, 0 Rejects
35.7/m utility Rate
Edited to add:
As you have 3 cards you will want to have 3 comma separated values for your GPU settings in the cgminer.conf
e.g.,
"worksize" : "256,256,256",
"gpu-fan" : "auto,auto,auto",
"gpu-powertune" : "20,20,20",
"thread-concurrency" : "14336,14336,14366",
I agree with these settings.
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