ccminer - KlausT / cuda issue

[AcesHigh70]

I am new to this and I'm currently trying to setup a single PC with 2 nvidia GTX 1070s.  I'm running Ubuntu 16.04 and compiled the KlausT ccminer off the cuda branch from github. 

My older mother board has AMD integrated graphics.  I'm currently not using it, but the drivers are still installed.

When I run ccminer and specify a single nvidia card (-d 0 or -d 1) the miner runs great.  If I don't specify the -d option or I specify -d 0,1, the fans on the nvidia cards immediately spin up and the machine completely freezes.  I haven't tweaked anything as far as the nvidia cards are concerned. 

The rig has a 600W power supply which I think would be fine for 2 o1070s.  In fact I turned the power limit down to 125 temporarily and tried that and it still didn't work.

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Here's how I start the mining when it freezes:

ccminer -a neoscrypt -o stratum+tcp://<pool>:<port> -u <user> -p <password>



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ccminer -n
ccminer 8.18-KlausT (64bit) for nVidia GPUs
Compiled with GCC 5.4 using Nvidia CUDA Toolkit 9.1

Based on pooler cpuminer 2.3.2 and the tpruvot@github fork
CUDA support by Christian Buchner, Christian H. and DJM34
Includes optimizations implemented by sp-hash, klaust, tpruvot and tsiv.

[2018-01-04 21:16:02] NVML GPU monitoring enabled.
GPU #0: SM 6.1 GeForce GTX 1070
GPU #1: SM 6.1 GeForce GTX 1070

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Any suggestions?

[wacko]

Any suggestions?

Did you try running two separate miner instances with one gpu per instance? So "-d 0" for the 1st instance and "-d 1" for the 2nd? Does it make your PC freeze? If it does, when and with which GPU does it happen? (run first the instance with "-d 0" and then "-d 1", and also try running "-d 1" first and then "-d 0")

[AcesHigh70]

Thanks for the suggestion.  I tried both and neither worked.  I eventually hooked up a dedicated power supply to the 2 Nvidia cards and it worked.  Power issue!  I thought for sure 600W would drive 2 of those cards and the MB/hard drive/CPU.

[wacko]

Thanks for the suggestion.  I tried both and neither worked.  I eventually hooked up a dedicated power supply to the 2 Nvidia cards and it worked.  Power issue!  I thought for sure 600W would drive 2 of those cards and the MB/hard drive/CPU.

Well 600W might be enough power for your rig, but not every 600W PSU can deliver all the power these GPUs need. Even if it's a high quality PSU its 12V line still might be divided into multiple rails, and that could result in instability when mining with both cards (not always possible to connect 2 cards + the rest of the system while keeping both GPUs well supplied). And if it's a cheap old PSU, then there's a good chance it can't really supply 600W at all (or it can, but the voltage will drop from 12V to 11V or something).