Topic: 7950 and cgminer questions (Read 5008 times)

Yes. Those place in my sample config that have 2 values separated by a comma, they are for each GPU.
So with 3 cards you should use... "kernel"         : "scrypt,scrypt,scrypt",

I'm also using the Frozr 7950 cards.
I would start with the default clock speeds & voltage.
Once your performance is good, then try squeezing a little more by increasing the clock speeds.
My experience was that this gave me a little extra, but having the config correct to start is more important.

Sorry I get it now.  You mean the clock core out of the box.  Mine are 960 also.

Not sure what default core means.  Sorry.  Id like to know what it means though so I can adjust this stuff myself in the future if/when I get different cards.

Whats the default core on your cards mines at 960

These are the exact cards Im using.

http://www.msi.com/product/vga/R7950-Twin-Frozr-3GD5-OC.html

What brand/model 7950 cards are they?

HW errors usually mean you have the intensity up too high.

If you are only getting 200 errors a day that's not too bad.

Do I also need to change this?

"kernel"         : "scrypt,scrypt",

to

"kernel"         : "scrypt,scrypt,scrypt",

Thanks again so much.

Thanks man Im now running with 0 HW errors, about the same mh/sec and my U is now at 9.5.  Should it be higher? 

Theres a couple things I changed though.  When just straight copy/pasting what you had, my 3rd card was barely running so I changed these settings from what you had.

"temp-overheat"         : "80,80,80",
"temp-cutoff"  : "90,90,90",
"temp-target"  : "70,70,70",


"intensity"      : "20,20,20",
"vectors"       : "1,1,1",

It just seemed right based on the other changes you made.  Once I did that, all cards are running great.  I had no idea whatsoever you could do any of this.  Ive only read one tutorial and your instructions are alot different but I love it.  Thanks so much!!

Wow thats FredDag.  I will try this later today.  Im such a newb with all of this.  Ill report back.  Sorry if I didnt post in the right area.  This is my first post after getting past the 4 hour mark forum reading mark.

I agree with these settings.

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://bitcointalksearch.org/topic/how-to-ltc-mining-overclocking-guide-79507850-175646

I 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",

Dude I can't get past 515 hash no matter what I try.

I would be happy with those speeds as long as everything's running stable.

If you don't already know about it, look at https://github.com/litecoin-project/litecoin/wiki/Mining-hardware-comparison for some different settings to try. 22400, 21712 and 24768 could be tried for thread concurrency, but if you're getting that kind of speed I really wouldn't worry about it.

Also this should probably be in the mining section ;-)

Hi I'm kinda new here but wanted to ask a question.  I am running cg miner with 3 7950s and mining litecoin.  My hash rate seems to be good but after reading, I read that my thread concurrency should be alot higher.  If I set it past 16320 it errors out.  I am also getting hardware errors that I heard you werent supposed to get.   I probably get closeto 200 hw errors per day.  I was wondering how to get my thread concurrency up and my hardware errors down.  I am running the 13.2 drivers.