I decided to build a gaming PC, so I recently bought an ASUS Radeon HD6970 2GB DirectCU II. When I asked for an optimal PSU choice I have been recommended an XFX Core 550W. So, I bought it, only to find out that it only has one 6pin PCI-E plug and one 6+2pin PCI-E. But the Radeon requires two PCI-E 8pin power connectors. There is a red LED glowing on the back of the VGA's PCB... It appears to me I've wasted money on this PSU, because it doesn't even have the needed connectors...
CPU: Intel Core i5-2500K @ 3.3GHz
VGA: ASUS Radeon HD6970 2GB DirectCU II
PSU: XFX Core 550W
RAM: A-DATA 8GB 1333 Gaming Series CL9
M/B: ASRock Extreme3 Gen3 Z68
Could you please give me some advice?
Is this PSU even enough to handle the rig?
I also saw a 2xMOLEX -> 8pin PCI-E adapter, would it be any good for me? The PSU has plenty of MOLEX connectors.
Thanks for the reply.
I did this now:
I connected the PSU's 6+2pin into the first 8pin socket.
The 6970 came with a 2x 6pin PCI-E -> 8pin PCI-E adapter, so I used it for the second socket, but I connected only one of the 6pin plugs, and it seems to work. But doesn't that limit my OC capabilities?
Yeah the 6970 DirectCUII from ASUS has 2 8 pin connectors. Very sexy.
Just have a look that the PSU can deliver enough current for the GPU, although I'm not so worried. Make sure you have the connections spread out accross the different 12V rails, ie; connect some through PCIe connectors, other leftovers via molex adapter you suggested
Well I'm using one PCIe 8pin connector, and the adapter that came with it that has 2 six pin to 8 pin, connected to that I have one of the six pin PCIe connectors, and using an adapter from dual molex to 6 pin. It's working fine here, no problems.
Moderator JSC stated ; Graphics cards use either 6 or 8 pin plugs for power. Do not use a 4 or 8 pin CPU power plug. They are wired differently. Using the wrong one will result in shorting 12 volts directly to ground.
Got the 2xMolex -> 8pin PCI-E adapter, and now the system works flawlessly.
Temperatures are good I guess, GPU: 29 C idle, 50 C at load; CPU: 23 C idle, 40 C at load. No OC yet, of course. Definitely need to try it soon.
In terms of whether you actually need to use both 8pin PCI-e power sockets on the graphics card; read the manual. My MSI HD5870 Lightning has two 8pin connectors, but the manual says only an 8+6 is actually required.
6pin connectors support 75W, 8pin support 150W. This is in addition to what it draws from the slot.
Good to hear it works though. I would suggest you're probably near the limit of what the PSU can handle though.