Radeon HD 5970 Only using one GPU, Hard Reset when 2 used?

[theoperator]

I appear to have a problem with my HD5970, and was wondering if any of you helpful folks have experienced similar, can offer advice, or just tell me not to worry about it?

Using Everest to monitor occupancy and temperatures, under load GPU1 gets hot quickly (and VRM very quickly), but GPU2 stays pretty chilly, and looking at performance, appears to stay at zero occupancy when playing games whereas GPU1 is fully loaded.

I fired up Furmark, in MultiGPU mode and when I click to start the test my system hard resets immediately. In single GPU mode Furmark works as expected. It seems fishy to me. Thoughts?

 

[lsv]

Do you have enough power?

 

[bryanW1995]

try out some games with one gpu disabled at a time and see if xfire is actually working. if it isn't it's either a card issue or psu issue.

 

[theoperator]

Could be power I guess, my 'SLI ready' 650w PSU seems rather small by today's standards, and I do have 3 hard drives and a bunch of USB stuff running.

I guess I could try unplugging all but the basics and see if that helps?

I can't seem to find a way to disable a specific GPU, is it buried in the driver options somewhere or do I need to install something extra like ATITools?

 

[mindwreck]

650 is barely above the minimum but it is enough to power the card with full load. try unplugging all the hdds cept the boot see how it goes

 

[Arsynic]

Power

 

[Meghan54]

... my 'SLI ready' 650w PSU seems rather small by today's standards,

The marketing term "SLI Ready" is really meaningless as far as power supplies go. While the seller is hoping it implies the marked ps is able to run cards in SLI mode, most times it only means it has two PCI-e connectors.

"SLI Certified by Nvidia" or "Crossfire Certifed by ATi/AMD", on the other hand, indicates the power supply has been tested doing just that....running a pair of cards in SLI/XFire mode.

Then there's the question of what 650W power supply you're trying to use. For instance, a Corsair HX-series or Seasonic X-series are vastly different power supplies with vastly better performance and capabilities than a CoolMax or OCZ 650W unit.

You've probably come up hard against what your current power supply can deliver on its +12V rail, and it may just be the brand and/or age of the power supply.

 

[theoperator]

OK, sounds reasonable. Upgrade time Thanks for the advice folks!

For the record I'm using this PSU: http://www.extremeoverclocking.com/reviews/cases/Akasa_AK-P650FF_1.html

Yes, it's rather old now. Any recommendations for a good modern replacement?

 

[tynopik]

the way the power is distributed between the rails is rather odd

For instance 12V4 only supplies 8 amps

you might want to try reallocating what rail powers what

 

[RavenSEAL]

Xfire Hd5970?!?!?650w?!?!?! WTF have you been smoking? time to get a corsair 850w...

 

[Cheesetogo]

Yeah, those rails are rather wonky. 650W should be enough assuming you aren't overclocking, but that PSU in particular looks pretty weak.

 

[theoperator]

Thanks all for your replies (even Ravenseal, despite the abuse ). I'm going to pick up a new PSU, most likely Corsair 850w

 

[Meghan54]

Good choice.

But your current power supply, while built by Enhance---a good OEM, btw---has a wonky rail distribution.

First, it's a group regulated power supply, an indication of an older design. Not necessarily bad, but not as refined as an independently regulated power supply.

Second, the way Enhance distributed the rails and their connectors is strange.

Your +12V1 and +12V2 rails power the 8-pin (2x4 EPS) cpu connector exclusively.

Your +12V3 rail is split between your PCI-e connectors and the 24-pin ATX main connector. (WTF?)

And the +12V4 rail powers your Molex and SATA connectors.

What this means is that you have only 16A, or 192W, available to your 5970 video card and it's not for the video card's exclusive use, either. It shares the rail with your motherboard's power requirements.

And while it was SLI certified by Nvidia, a good thing, it was certified for much older generation cards.....cards prior to the 8800 series.

Link to Nvidia's SLI component page.....your Akasa power supply only shows up in the "other not listed SLI configurations" section. http://www.slizone.com/object/slizone_build_psu.html

Of course, a nice Corsair 850W would be a good replacement. The question is a TX or HX. The HX's are more "enthusiast" oriented.....slightly better internal components, modular cables, slightly better electrical performance than the TX series, but at higher prices. On the other hand, the TX's are very capable units and shouldn't be overlooked, esp. for their price.....that is if you can deal with all hardwired cables.

 

[TemjinGold]

OP: Just to clarify, you are using ONE 5970, and not TWO, right? If yes, a nice quality 650watt will be fine (any of the brands recommended earlier.) If you are using TWO cards, then you need that 850watt.

 

[theoperator]

Just one 5970 yep Thanks Meghan for the analysis also - I think i'll go for the HX, I'm planning a new rig (incorporating the 5970) and like the modular cabling to keep things tidy.