Settings for mixed GPUs

[baka]

I have a 7750 and a 5870 that I want to use for LTC mining. What settings are best for this combination?

[BrainShutdown]

Start here
https://github.com/litecoin-project/litecoin/wiki/Mining-hardware-comparison#wiki-ATI_AMD_GPUs

[forsetifox]

Hiya. I've got a 6670 and a 7790 and they do NOT liking playing nice together when using scrypt. Here is my command line that I use.

cgminer.exe -o stratum+tcp://us.wemineltc.com:80 -u worker -p workerpassword --scrypt --thread-concurrency 8196 -w 64 -I 13,10 -s 1 -Q 0 -E 1

The 8196 thread concurrency is the only setting I've found that doesn't crash cgminer.

[MaGNeT]

What if you launch Cgminer 2 times by defining -d 0 and -d 1 seperately in each line?

[bee7]

Hiya. I've got a 6670 and a 7790 and they do NOT liking playing nice together when using scrypt. Here is my command line that I use.

cgminer.exe -o stratum+tcp://us.wemineltc.com:80 -u worker -p workerpassword --scrypt --thread-concurrency 8196 -w 64 -I 13,10 -s 1 -Q 0 -E 1

The 8196 thread concurrency is the only setting I've found that doesn't crash cgminer.

Did you try to specify appropriate thread concurrency & work pool size for each gpu (the same way as you specified different intensities, e.g. -w 64,128)?

Edit:  not 8196, but 8192, I suppose.

[forsetifox]

What if you launch Cgminer 2 times by defining -d 0 and -d 1 seperately in each line?

Tried that as well. Almost always does not work. If I were to disable an adapter if I recall correctly it does work normally.

[forsetifox]

Hiya. I've got a 6670 and a 7790 and they do NOT liking playing nice together when using scrypt. Here is my command line that I use.

cgminer.exe -o stratum+tcp://us.wemineltc.com:80 -u worker -p workerpassword --scrypt --thread-concurrency 8196 -w 64 -I 13,10 -s 1 -Q 0 -E 1

The 8196 thread concurrency is the only setting I've found that doesn't crash cgminer.

Did you try to specify appropriate thread concurrency & work pool size for each gpu (the same way as you specified different intensities, e.g. -w 64,128)?

Edit:  not 8196, but 8192, I suppose.

I've never tried it but I don't think you can use multiple --thread-concurrency settings at once. I'll have to try that and see if it works.

[MashRinx]

I don't like posting this because I'm a BIG cgminer fan, but I have had a lot of issues running cgminer in a couple different rigs with mismatched cards.  3.2.0 is better and 3.2.1 may be better still (I've not had a chance to test it yet), but I've had better luck with bfgminer in these cases.  There are so many different variables to getting scrypt mining running, let alone running well, that I wouldn't be surprised at all if this is something I'm doing wrong, but just wanted to throw this out there in case it gets you mining sooner, even while continuing to troubleshoot the original issue.

Good luck!

[bee7]

I've never tried it but I don't think you can use multiple --thread-concurrency settings at once. I'll have to try that and see if it works.

cgminer 3.1.0 help:

--thread-concurrency <arg> Set GPU thread concurrency for scrypt mining, comma separated

Also, i just checked the code. Any kernel, the scrypt.cl as well is selected on per-GPU basis as well as its parameters. So it must be fine to use different parameters.

Edit: the only thing should fail probably is selecting scrypt kernel for one adapter and any sha256 kernel for another as '-a scrypt' switch controls not only the selection of the scrypt.cl kernel