Do I need to upgrade my PSU?

[Tobes]

Hello,

So I have my finger over buying another 7950 and having them in Xfire. But I realised I don't have a spare PCI-E power cable (I know they come with molex-pci-e in the box). I have used pretty much all the sockets except one on my modular PSU, Corsair HX620. So I could use the last one and plug in the molex cable. But with it being the last one I'm wondering if the PSU will power it all.

My current specs:

256GB Samsung 840 Pro
120GB Kingston
250GB HDD
1TB HDD
i5 3570K
Gigabyte GA-Z77X-UD5H
H100i
Asus Essence STX

Plus 2x 7950.

Think it will be fine or should I be thinking about spending another £100?

 

[snips86x]

On the safe side, I'd get a 750w:

YOUR BASKET
1 x Corsair Enthusiast Series TX 750W V2 High Performance '80 Plus Bronze' Power Supply (CP-9020042-UK) £94.99
1 x BeQuiet Pure Power L8 630W '80 Plus Bronze' Modular Power Supply - With 120mm Silent Wing Fan Built in £79.99
1 x XFX Pro Series 750W XXX Edition Modular '80 Plus Bronze' Power Supply £79.99
Total : £267.58 (includes shipping : £10.50).

 

[linwelin]

hmmm i think you might need a higher W PSU if you're wanting to run Dual cards, it might be fine, but i think it will be pushing it, up to you.

Try this and see, it will give you a rough guide
http://www.thermaltake.outervision.com/

 

[Tobes]

555W.

No overclocking put in though.

Yeah I might up it to s 750W. How will I know if my current PSU isn't up for the job? What symptoms will show?

 

[dacads]

I thought the PSU calculators over-estimate anyway? What's more important is the 12v rating so you'll need 46 Amps or greater and four 6-pin PCI Express power connectors. I believe the HX620 has 54a in total over 3 rails. So that will allow room for OC your CPU as well.

There's no doubt wattage is frequently over-estimated

 

[linwelin]

555W.

No overclocking put in though.

Yeah I might up it to s 750W. How will I know if my current PSU isn't up for the job? What symptoms will show?

your system will just crash i would have thought