Crossfire Issue...Can't figure it out

[nbrikha89]

I ran FurMark and passed the 15 minute burn in. The one thing that stood out for me...the first video card was at 1.125V at full load but the second was at 1.2V at full load. Is that just how the cards are referenced? Or do I not have enough juice in my PSU?

 

[OhSnapWord]

The PSU might not have enough juice. According to this:

Newegg.com - Recommended Power Supply Calculator.

You need a PSU capable of 585W. Personally, I think 600W is cutting it close, I would go up to at least 650W. Not enough power would certainly explain instability.

 

[Macmaster4k2]

only reason i could think of is that the cards are not compatible with one another since they are different brands? highly unlikely but i know of companies in general that would do things like that

 

[OhSnapWord]

The cards don't have to be the same brands but they do have to have the same GPU series.

e.g. one card can be a 5770 and the other can be a 5750

 

[Indigo]

The Newegg power supply calculator overestimates (by a large margin) power supply requirements. A better tool to use is eXtreme Power Supply Calculator

 

[nbrikha89]

It's about the same. That site told me on multiple accounts that I need 550W ish, after all my fans and such are accounted for. However, I still find that I have instability until I unplug most my fans. I believe that I just have a lack of enough wattage on my 12V rail. My fault for buying a PSU for just under 60 bucks. It's also 3 years old, and no 80 Plus certificate. I'm fine for now, but I know in order to fix the instability indefinitely, I'll need more power. Plus, it seems most games aren't optimized for AMD cards, let alone crossfire. My next big GPU purchase will probably be nVidia, though they take even more power. Thanks for the help everyone!