Thinking of Crossfire.. do I have enough power?

[SmCaudata]

I see the power consumption numbers for various crossfire setups, but I'm not sure if my stuff is going to use more power.

I have a corsair 650tx that is a few years old (before the 80plus certifications were made.) I just picked up a 6950 and it gave me a huge performance boost. I'm thinking of going to EyeFinity and wondering what you guys think of the power output.

Rest of system.
Q9550 at 3.4GHz at stock voltage. 1.1V
4x 1GB Ram at 2.1V (overclocked for CAS4 I could bump down to CAS5 and 1.8V.)
DFI Lanparty board. No overvolting on any parts.
MSI 6950 not unlocked.
2x 1tb Samsung F3 in Raid 1
60GB SSD.
Then miscilaneous USB devices and such.

Am I going to need to upgrade my PSU?

 

[Jhatfie]

I would say most likely you will need to upgrade. I think a brand new quality 650W would struggle with two 6950's in crossfire but might be okay, but once you factor in the age of your unit and the degrading of it's capacitors over that time it is likely that it will be overwhelmed under full load.

 

[SparkyJJO]

I disagree.

You're looking at an absolute max of 450W if everything is at full blast. That is still only 69% of the capability of the Corsair 650TX, not pushing it hard at all.

No sense in replacing the power supply.

 

[TemjinGold]

OP: Buy the extra card and plug it in. Fire up the most power intensive thing you plan on doing and play around with it for like an hour. If it crashes, you need a new PSU. It shouldn't crash though unless there's something wrong with the PSU to begin with. You have a quality unit, so the worst that can happen is you have to reboot. Most people recommending big PSUs honestly have no clue how little power things really use.