Was having problems a few days ago with my setup, ran through every possability and ended up rma the gpu, received replacement today and still the same problems.
Thermaltake 875w psu
Asus p5q deluxe mobo (updated the bios)
6gb ram
asus gtx 470
Put the replacement in, re installed windows and all updates.
The gpu shows in device manager and is adjustable with afterburner. The problem comes when i start boinc, after a few seconds the progress bar moves say .025% then freezes, the whole think locks up and the only way out is to restart.
Have unplugged any peripherals i do not need and even additional fans, still the same boots into windows fine but as soon as it starts a wu in boinc it freezes.
Checked and double checked the cabling and psu all is cabled correctly, the psu can power 2 pcie gpu and came with 2 x 8pin to 6 pin and 2 x 8pin to 6+2 pin cables below is a pic. The 4 black coloured connections are for peripherals the red for the pcie
Done everything i can think of and i am completely stumped i just don't know any ideas appreciated
Am not even sure the problem is the psu but everything else checks out ok and the 3 green indicator lights on the psu are all a go
