New graphics card BSOD's with 4 sticks of RAM

[coolhandluke]

Hello! this is really baffling me and i'm running out of ideas. So, i've just upgraded my graphics card from a Sapphire HD5770 to a Sapphire HD7850. As soon as windows boots up (windows 7 64bit) i get a BSOD within about 20-30 seconds without fail, same thing happens in safe mode. Drivers did manage to install though.

I've narrowed it down to a RAM issue, except i don't think the RAM is faulty because it tests out fine in memtest and it worked fine with my old graphics card. I found this out by pulling out a stick at a time, and it became stable with 2 sticks in, no matter which 2, and no matter which slots.

A bit of research lead me to beleive i needed to bump up the voltage, indeed it was only on 1.8, so once i gradually got up to 2.3 volts all seemed good, i ran furmark for 15 mins and it was fine, everything was stable it seemed. Then i plugged all my periperals back in, extra hard drive ect. and back to square 1

So i disconnected all the peripherals that i connected thinking it would return to normal, but it's BSODing again! So i've currently got it running on 2 sticks of RAM with everything setup and i've had no issue with just 2 sticks installed yet.

My system is as follows:
core2quad q6600
evga 680i motherboard
4 x 1gb ddr 800
600 watt be quiet psu
amd hd7850

I plan on upgrading the rest of the system at some point, just not sure why the upgrade in the graphics card is causing this problem. Any advice would be greatly appreciated.

 

[patonb]

I wonder if your power supply i8s craping out thus you are not getting enough power from it.
Be quits arre not the best quality so realistically I'd expect around 550W tops out of it new, and add age into it and it'll be struggling.

 

[coolhandluke]

I was thinking about that, it is a few years old now. Well the minimum watts is 500, and the spec on the PSU says It's got quad 18a 12v rails, is that not enough? it would explain the symptoms though!

 

[coolhandluke]

I'd just like to post an update on this and tell you the problem appears to be solved. I went on the hunch that it was the power supply (thanks to the backup from patonb) so i replaced the old be quiet 600w with a corsair 750w and it's been stable ever since. Even with the RAM at 1.8v it's stable. Before it wouldn't last more than 20 seconds without crashing on the old PSU at that voltage!
I think my old PSU just didn't have enough amps, because of it's split rails it only had 18 amp on the 12v rails, which just isn't enough for mid range graphics cards. The new one has a combined rating of 62 amps on the 12v rail.