Second 5870 on the way but is my PSU up to Crossfire

[MoRT489]

Second 5870 on the way but is my HX620 up to Crossfire

Hi chaps

I decided to get myself a 2nd 5870 for crossfire and worry about the PSU later but I'm thinking what to do now. I have a Corsair HX620 PSU and my brother has a Thermaltake Toughpower 750W (running Q6600 and GTX260).

Now I know that a 5870 crossfire system pulls close to 600W from the wall so I'm wondering if it's worth swapping my PSU with my brother's to make sure I have enough of an overhead for stability and overclocking?

The gfx cards wont be clocked to start with but my CPU is (3.8GHz @ 1.2v) so I understand this will increase my overall power draw.

So what do u think - should i keep the HX620 or swap over to my bro's Toughpower 750W? Is the Toughpower good for 600W+ draw?

 

[MoRT489]

how would the corsair be ok if the power peaks at 750? Something to do with built in safeguards on the HX620?

Dont want to risk the HX620 going pop but also dont want to take everything out of the case if it's going to work fine.

 

[MoRT489]

Where di u get 360W from

Guru3d suggests:

Radeon HD 5870 CrossfireX (2-way)
A second card requires you to add another 188 Watts. You need a 700+ Watt power supply unit if you use it in a high-end system. That power supply needs to have (in total accumulated) at least 55~60 Amps available on the +12 volt rails.

Tom's Hardware rates the max power draw at 561W http://www.tomshardware.com/reviews/radeon-hd-5870,2422-20.html.

ATI itself says minimum 600W psu.

 

[MoRT489]

Seems to be running fine on HX620