I am wondering if I can run either a Radeon 6850 or 6870 on my 400W Corsair PSU.
My current specs are: CPU i3 2100. HDD Samsung Spinpoint F3 1TB. 8gb ram.
A Corsair 400 W is a good enough PSU for cards upto Radeon HD 6870, but you have to use a 6 pin adapter cable. If you have the spare cable (normally comes with the card) you can use a Radeon 6870 or else a Radeon 6850 should be ok.
no, the requirement of 6850 is 500watts or greater.
AMD says 500w as an extra considering cheap quality PSU's NOT from high quality brands like Corsair, Cooler Masters, Antec etc
One of my systems has an OC'd Q9550, 4 GB RAM, a GTX260 - a card with similar power requirements to a 6870, a Gigabyte EP45-UD3P motherboard, 3 hard drives and an optical, and a Soundblaster card all powered by a Corsair 750TX.
Running 3 instances of Prime95 to load the CPU and 3DMark06 to load the GPU, it pulls 375 watts from the wall as measured by my Kill-a-Watt meter. Figuring 80% efficiency, the system pulls 300 watts from the PSU.