Do I really need to up my PSU ?

[GameOfMoans]

Hi Folks, I've just built a gaming rig from some old parts I had, but mostly new - Asus Rampage IV, i7 4930k, Corsaid H100i, 32 gb ram from old machine, 2 x Radeon 7870 in crossfire, Cooler Master Cosmos 2 case....

I decided just to try it with my Corsair AX 750 watt PSU...and seemed to be fine last night, but only had time for a quick try of BF4

I will be upping the GPU with probably Radeon R9 290s....

Do I need extra power from say the Corsair 1200i ? Or is this just overkill ?

 

[Outlander_04]

http://www.realhardtechx.com/index_archivos/Page362.htm

 

[Novuake]

An AX 750W is capable of running 2 R9 290s if you keep overclocking to a minimum. So do not worry about it.

 

[siddharthmukul007]

if you wish to have 2 r9 290s...i suggest you upgrade your psu.

but you should be good for just 1 290

 

[GameOfMoans]

Cheers for the replies, I'll probably up it when I up the GPUs...it was more, can the 750watt run the 2 Radeon 7870's in the mean time ? I made a massive mistake in buying an Alienware Aurorar4 in June of 2012 where these GPU's came from, and it had a 600watt psu...so I thought a 750 would do...but going forward I guess running 2 x 4gb cards will require more stable power supply to run well...

 

[siddharthmukul007]

yes 750w will be able to run 2 7870s fine

 

[Novuake]

Cheers for the replies, I'll probably up it when I up the GPUs...it was more, can the 750watt run the 2 Radeon 7870's in the mean time ? I made a massive mistake in buying an Alienware Aurorar4 in June of 2012 where these GPU's came from, and it had a 600watt psu...so I thought a 750 would do...but going forward I guess running 2 x 4gb cards will require more stable power supply to run well...

No it does not need any more power.
The AX750 is one of the best around.
Here is a review :
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=236

Here is a graph of total power consumptions on a system with an R9 290 and Intel Core i7-4960X @ 4.2GHz.

So as you can see the TOTAL system requirement is only 384 under max load.
With your excellent 750 watt you still have another 366W for a second R9 290. Which is way more than enough.

 

[GameOfMoans]

Great, thanks for that....so so glad I took the decision to self build....very satisfying not to mention it's cheaper too !

 

[GameOfMoans]

Actually I made a mistake...it's the CX750M I have, not the AX....I think the only difference is the CX is partially modular...the 24 pin and CPU cables are not modular...the remainer are.

 

[Novuake]

Actually I made a mistake...it's the CX750M I have, not the AX....I think the only difference is the CX is partially modular...the 24 pin and CPU cables are not modular...the remainer are.

OK no, lol the CX is a lot different to the AX. 2 HD7870s on the CX is fine. But not 2 R9 290s.

The CX series is very much overrated on wattage and not meant to run at high load.