Do I have to buy a new power supply?

[julien329]

I want to run two 6850's in Crossfire. I i just wan to know if my power supply can actualy hande it.

My spec are :

i5 2500k
1 dvd drive
a wireless internet card
1 Tb hard drive
8g ram 1666
1 radeon 6850 (maybe 2 soon)
actual power supply 600w (Edit: Corsair Builder Series CX600)

 

[sadams04]

Maybe... The HD 6850 pulls about 230 watts at full load. With two GPUs and the rest of the system you might be able to skate by with a good 600w PSU, however, if you haven't invested in a good power supply now would be the time. Which power supply do you have (be specific)?

 

[julien329]

My power supply is a Corsair Builder Series CX600

 

[jsc]

A 600CX has a single 40 amp 12 volt rail.

A pair of 6850's pulls about 20 amps.

One of my systems has an OC'd Q9550, 4 GB RAM, a GTX260 - a card with similar power requirements to yours, 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.

Add a second 6850 and you are up around 450 watts. A 600Cx will be enough, but because I prefer to operate a PSU at around 50% of capacity, I would want a little larger PSU.

 

[julien329]

But is it doangerous for my entire system to run with my 600CX?