Second 5870 causing BSOD

Hey guys, I'm absolutely stumped right now....

I was having severe stability issues with my setup and pulled it apart to figure out exactly what the problem is. I was getting constant BSOD with errors 101 and 9C. I've since changed literally every part and am currently running stable with a single 5870. Adding the second card and booting up causes a BSOD within minutes.

With the single card in I can OC the CPU (i7 920 D0 ----> now an i7 930) and run through linx or any other benchmarking suite. Installing the second card and I can't open firefox without a crash.

Seems like a PSU issue right? Well I figured maybe my corsair HX1000 had died on me and wasn't producing it's rated power. i took this as an opportunity to upgrade and picked up a Silverstone ST1500 and... same problem.

I've gone through everything.... tried on an EVGA classified that I know works, and on a brand new Gigabyte X58A UD5. Ran memtest and tried two sets of working corsair ram. Tried two different CPU's. Reseated several times and am now running on air for easier swapping of parts.

Any ideas?

At stock settings, a good 750watt PSU would've been able to run 2x 5870s + i7.
(2x 225watts+ ~200watts) So your PSU is perfectly fine.

Have you tried testing the other 5870 separately? The card might be bad.

I wasn't concerned about the power supply not having enough power. I had run it with 2 GTX295's for almost a year. I did however have a bad power surge that shut everything down and thought that it may have damaged the HX1000. I picked up a ST1500 because it's fully modular, I can use it for my upcoming build, and because I got a good price on it.

I have tested both 5870's separately as well... I ran with on of them for several days and had no problems... now I'm running with the other, also no problems.

Yeah, I plan on trying that this evening. Hopefully it works out!