620W for 7870 Xfire?

So I plan on doing a hardware upgrade (replacing my 7770 with 2 7870s in Xfire) 

Specifically these 



This was the cheapest PSU (69.99 after mail in rebate) At about 600-650 watts, with 4 6 pin connectors, modular, and wont look wack with my black blue color scheme 


now my question is will it power both of those cards?

I also have an FX-6300 (plan on overclocking it to abot 4.4ghz)

Asrock 970 Extreme 4 Mobo

2 x 4Gb of corsair Vengence 

2 Hdd

and probalbly about 5 case fans

I used a calculator and at 100% TDP

It says my system will use around 527W

That didn't sound right to me so I canme here to make sure.

And I didn't want to create another post just for this one question but can My future rig put out a stable 120fps on most games with medium to high settings?

Almost 2 days and not a single reply ... 

get a cx 750 from corsair and that should be fine.  Also make sure you get a really good oc on your cpu to eliminalte any bottleneck.

why on earth would you go multi gpu if you don't already have one?

get a 7970 or a 770

nope not with 7870

It's a bad idea to crossfire mid-range cards. You can get a 7970 for less, and the PSU will be adequate and it will probably give you more performance than two 7870s. 


The CX 750W only has 2 6 pin connectors

Why go with multi GPU ... Why not?

Why is it a bad idea ? Are there a lot of Issues with crossfiring these 2 cards?

And I'm mainly going to play Battlefield 4 with this rig ... Heavily AMD optimized which means huge Up scaling with crossfire ... As for the price sapphires 7870 is currently $160 on newegg so picking up 2 ON SALE is in some cases cheaper than a 7970 .... And finally (as dumb as this may sound) my mobo supports 3 way x fire so not using the feature even partially ( 2 way Xfire) seems like a huge waste + the his iceq coolers are super aesthetically pleasing ... But if you can present me valid arguments against getting those 2 cards I'm open to suggestions as even I don't know everything ...

multi-gpu has too many issues to name, mostly very few games can actually utilize it decently

you won't get more than the sum of your parts, you'll get less, basically if you put in 2480 stream cores you won't get the performance of 3000, you probably won't even get the performance of 2000

your motherboard doesn't actually support 3 way crossfire, it does, but each card would get hardly any bandwith, making it a marketing gimmic that is counter productive in practice, the 970 chipset can only run 1 card at full bandwith

and back to the utilizing it decently, a fair ammount of games could run worse than with a single card, or not support a second at all, not to mention all the screen tearing and latency issues i've been hearing about, they say there's a fix comming, but that's not something to count on deffinatly happening

So you too are suggesting I pick up a single 7970? Even if it can't push 120fps very easily ... And in terms of games not utilizing it correctly I'm mainly going to play battlefield which utilizes crossfire very well.

Well i'm not upgrading immediately but i will put some thought into it ... can someone please confirm to me that the PSU I chose will work for eithier a single 7970 or 2 7870s in crossfire?


Tom's hardware question answer "

For a system using two Radeon HD 7870 graphics cards in 2-way CrossFireX mode AMD specifies a minimum of an 600 Watt or greater power supply. The power supply should also have a combined +12 Volt continuous current rating of 39 Amps or greater and have at least four 6-pin PCI Express supplementary power connectors.

Total Power Supply Wattage is NOT the crucial factor in power supply selection!!! Total Continuous Amperage Available on the +12V Rail(s) is the most important factor.

If you're overclocking the CPU you will need to add some extra amperage to the combined +12 Volt continuous current rating recommended above to handle it."

I agree with the cx750m as being the best value for money.


Has 4x pcie, would run either a 7970 or 2x7870's with ease and still have plenty of headroom. Has longer warranty as well and imho a much better build quality.


What's the difference between the CX 750 you recommended and the hx750 other then the hx being modular but the cx has the 750m sooo?


look them up, I use this list to get an idea on the quality you can expect from a psu brand or series from a brand

hx is higher than cx on tier list

Xfire has micro stutter,scaling issues,bad optimization,more power draw.

A single powerful card will be better than 2 less powerful ones.

For psu you can only trust 3 manufactuers.Seasonic,Superflower and Enermax.Seasonic makes the high end Antecs and Corsairs and all XFX.Enermax makes all Lepa psus.

Stay away from Channel Well Antecs and Corsairs,they aren't good.Stay away from FSP or and brand made by FSP Group.