I have a question on if the power supply I have is big enough for my system. I have a amd 5000 be , 1 4850 , dvd rom ,dvd rw,4 gig ddr2, and 1 hard drive on a msi am2 790x motherboard. I am looking into getting another 4850 to run in crossfire and going with a amd phenom 9850. The power supply that I have is an antec 550w true power 2.0.

thanks for you input

Now the only thing that i found is that a 4850 requires in crossfire a 550 w or greater power supply but with a 125w cpu is my 550w enough i dont find anything stating what setup is used when figuring there requirments to say 550w or better

a little confused

The 4850s in crossfire will use 200w at load. Your system should be fine with a 550w PSU.
http://www.atomicmpc.com.au/forums [...] c=7&t=9354

Only a fraction of total wattage is routed to the 12v rail that powers graphics card, cpu, hdds. Also, even the most efficient psu has around 80% efficiency under optimal conditions. Under typical usage, it's lower. Effect of aging and ampage limitations also cut down power available in reality. Depending on 12v rail ampage and fluctuation at high load, 550w is cutting it very close, if it works at all.

my power supply has >70% efficiency and my outputs are: +3.3V@32A, +5V@40A, +12V1@19A, +12V2@19A, -12V@1A, +5VSB@2A

if this help seeing if it will work like i said tring to find out info on a psu with set i get conflict results but thanks for all the info so far

It's not enough. 12v rampage is too low to support 2 4850s plus a quad core cpu. It'll boot up and run on idle, but crush on high load.

Ok what psu would do for 2 4850 and a phenom 9850

700w+ with good 12v rail ratings.

I would recommend Thermaltake, OCZ, or Corsair of 650+ Wattage. Although you can get cheaper power supplies that state higher wattages; it is all about the brand, and efficiency of the PSU. Stick with a decent brand, and 650+ watts, and you are good.

My two cents