Crossfire 7850 will 750w suffice?

[conb123]

Hey I currently have a single msi r7850 twin frozr III card and was thinking of getting a second to upgrade to crossfire, here are my current specs:-

Antec 1100
Intel i5 3570k @ 4.0Ghz
Gigabyte Z77X-UD3
MSI R7850 Twin Frozr III
Corsair H100i
2x 60GB SSD
1x 1TB WD Caviar Black HDD
Corsair TX650W
16GB Kingston HyperX Genesis RAM

I understand that getting a second 7850 will mean more power requirement. I was consdering this http://www.scan.co.uk/products/750w-...ps-12v-fan-atx do you think this PSU will be enough or would I need 850?

[kalniel]

Your existing 650W would be fine. I would keep that over the one you link to.

[kompukare]

Your existing 650W would be fine. I would keep that over the one you link to.

+1. What kalniel said.

The max TPU were able to get a 7850 to draw using Furmark was 119W. So say a generous max 250W for two of them.
http://www.techpowerup.com/reviews/P...S_Plus/26.html

The rest of your system is fairly frugal and that 650TX PSU of yours should be fine at it's actual rating even if it's the CTW version and not the Seasonic one.
http://www.realhardtechx.com/index_archivos/Page447.htm

The Corsair CX750 is also CTW so it's not likely to be any better. Do wish Corsair would stick to one manufacturer for one series though. Not happy with manufacturers who keep switching since it always makes me think they're trying a bait and switch strategy.

[Willzzz]

Yeah 650w is plenty for 7850 CF.

[conb123]

Oh well that's welcome news, will save me some pennies, the PSU is the old non modular tx650, I got as an RMA must of been nearly a year ago now

[kompukare]

Oh well that's welcome news, will save me some pennies, the PSU is the old non modular tx650, I got as an RMA must of been nearly a year ago now

Fairly sure that's the CWT version. If I was spending £75 I'd rather get the XFX 650W for £66 which is Seasonic:
http://www.scan.co.uk/products/650w-...-quiet-fan-atx

than a CWT modular one for £75. Or if the budget was £75 I'd get the 650W XFX semi modular. CWT are ok but not at these kind of prices.

[d3m0n1q_733rz]

While some might not agree, I think springing for a 80+ platinum is a good idea. If you're going to have it on all of the time, it will drop power usage a bit and help your components to work a little more efficiently. For example, I have 4 x 2GB RAM chips that I could only use 2 of at any given point in time without the system failing. Once I upgraded my PSU to a platinum, all 4 worked great together.
It's really up to you. I'm using a multi-railed one and I'm thrilled with it.

[karl751]

I would be more happy with a 750w personally, but the 650w should be ok

[fozan1072]

You PSU should be enough.

[Butuz]

There's no should about it your 650w WILL be enough. I've got one rig with 3770k @ 4.5 and 2 x 7970 and that pulls 500-600w from the wall. 7850s is easy compared to that!

Butuz

[pastymuncher]

Stick with the TX650, it's more than enough for your rig and a pair of 7850's.

[Macadee]

I ran 2 heavily overclocked 7850's on a 650w Antec so your current (sic) PSU will be fine