Need Help with Multi GPU (Sapphire 7970) Rig
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Hi all. I have set up a rig but am having difficulty getting it to work with more than one Sapphire 7970 GPU. Here are the fundamental parts of this rig
ASRock 970 Extreme Mobo
AMD Athlon 64 X2 5000+ 2.6 GHz 1MB Dual-Core
4x4 GEIL DDR3 1600Mhz memory
3 Sapphire 7970 (Device Managers shows two of them when I have two plugged in)
cgminer 3.7.2
AMD 13.251 drivers
AMD SDK 2.9I used the setting in the following thread with a single card and everything works perfectly:
http://forum.feathercoin.com/index.php?topic=2555.0IF I power down and add a card, CGMIner will start but as soon as it starts mining the screen goes white (sometimes blue) and it does not appear to be doing anything. If I RDP to it and start CGminer from the RDP session it shows one live GPU and one dead in cgminer. I don’t entirely trust this because when I rdp to it with a single card the system gets confused and can’t report card temp or fan speed.
I’ve also tries running CGminer with a minimal set of variables and get the same result. -
Some how I hit send by accident, here’s the rest of my post:
Please help if you can, Beating my head against the rig isn’t helping and it hurts too! :)
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What power supply are you using?
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ITs cheap. It an MDX 1050 Watt P/S. With one card it’s pulling 350W measured in line at the power plug.
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It’s so cheep I can’t even get google to dig it up!
Do you know if it is single ore multi-rail? If you have one card working fine, and things only start to play up when you and another this sounds like it could be power related,
What happens when you go to 2 cards?
Are you using risers? if so powered or un-powered? -
Thanks Uncle!
I really had my head up my A$$ on this one. It was absolutely the power supply causing this issue. I have risers powered and unpowered but was not using them. I had the cards straight into the MOBO. At least until I could get the rig up and running at which time I would put them on risers. I had another P/S (another el cheapo) 450W that I used to power the second card directly and lo and behold. I had two cards hashing away. For about 15 minutes when the second powere supply puked and blew a capacitor. I doubt any of these cheap poer supplies can actually supply the amount of power they are rated for. I guess I’ll have to order me a seasonic or equivalent. I’m torn between trying to use one big ass P/S to power three cards or a medium one to do one card and the mobo and individual smaller ones for each GPU.Any thoughts on that? I’ll look through the forums as well to see what I find.