Bitcoin Forum

Hi Noobie here

I recently got into mining and bought 2 x 7950 sapphire gpus as well as a nox psu http://www.nox-xtreme.com/en/product/urano-tx-850w/56/ all brand new.

Only been running the rig for like a week and a half but it kept crashing at 900/1250 settings and yesterday the psu just buckled.

Is this a sign of a crappy psu or was this just a faulty one? and should I exchange it for another NOX or should I get a different brand?

Thanks

How much watts you have at wall ? You should use max 700W from 850w PSU. My overclocked 5850 has 250W and MB+CPU 150W for example

You can check the size here:

http://www.extreme.outervision.com/psucalculatorlite.jsp (http://www.extreme.outervision.com/psucalculatorlite.jsp)

Not sure about the wall. All I have in the rig is a 500gb hdd, anthlon II 270 cpu, 4gb stick of ram and the 2 gpus.

After the psu buckled I replaced it with a 750W psu and its running fine but I was hoping on eventually adding another card like  R9 280x or 290x.

I know i'll need a new psu for it but don't know which one will be best. Any suggestions on brands?

Thanks for the link xblade. Put in my set up and it says 393w does that seem a little low?

Depends on your system but I think power supplies have always been over sold with a bigger is better attitude. Unless
you  have a lot of disks a 400w power supply is pretty good size. I know I run a AMD fx8350, 1 disk and 2 7950 GPU's on a 400w with no problems.

Cool thanks for the replies very helpful

You didn't mention what brand you are using, or where you live. Some areas of the world have dodgy power with lots of brownouts, but usually it's a crappy PSU. You are using well under the recommended 80% of the PSU, so it is either the PSU, or the power going to it.

I would replace it and see what happens.

Corsair and Seasonic. EVGA makes some pretty good PSUs as well, but they are pretty new in the power supply scene.

@Mightymoo It's not very hard to understand this process anyways yes try to get a different brand.

get a better one

just got my new rig setup.

corsair axi 1200w psu powering 3 x sapphire r9 290's overclocked np atm but sometimes I get black  or blue screens which I believe is driver issue.

posted a question on how to use dual psu to power rest of my cards.

get a good quality psu imo.

The OP's power supply looks like an OEM that only sells in Spanish-speaking areas. It looks like it comes from deep in generic Guang Dong China; the company lies and says they have manufacturing facilities when these are probably CWT-built. The linked page even has a picture of a Jun-Fu capacitor, which should be in the hall of shame instead of a feature. Not well received by those who know this stuff: http://www.jonnyguru.com/forums/showthread.php?t=9570

That being said, if you are running at anything other than the stock speed, you are not guaranteed to have a system that doesn't crash all over the place. Add to that, two GPUs doing Bitcoin mining need lots of case cooling or an open case with fans right on them.