I have 2 7970s in crossfire (Because I'm a fucking retard) and i bought a EVGA PSU because i thought it would be half decent...
I was wanting to replace it so it's either an Corsair HX750 or an XFX Pro 750W.
Which would be best or is there a better one for around the same price range?
Thanks for the help.
What watts is your current PSU and any reason for the ugrade
The 7970 has a TDP of around 300W (more when overclocked) .... so if you have two of them in crossfire, I'd be pretty picky about the PSU ....
And .... Yeah, I'd probably rather choose something with at least 800W and 80+Gold.
If you take a worst case scenario with a FX-9590 and some WD Black or reds into the picture I guess 850W would even be way better.
But still .... to be on the safe side, I'd take at least 800W
TDP does not represent the power consumed. the 7970 consumes 400W under full load.
You two are both dreadfully misinformed...
TDP refers to the maximum heat output the card can give under maximum load. As for consuming up to 400 watts, it simply isn't possible and in most cases would cause a fire.
The 7970 has at most 2x8 pin PCI-E connectors. From these it can receive 150 watts from each. 150x2=300. It is also connected to a PCI-E lane, which can supply it with 75 watts. 300+75=375.
400 > 375 = fire
The XFX unit will be better because their quality is pretty much the highest you can get in any PSU; most XFX units are re-branded Seasonic units.
As for the second part: what kind of price range? There may be something better.
I was hoping for around £50 ($85), maybe £80 ($135) at most
750W EVGA 80+ gold but i have been informed that EVGA PSUs are pretty much useless for crossfire which was causing it to just shut down, so i just need something that can handle the cards
That's just standard they want you to say with in. You can exceed it and there wont be a problem. The 6990 and GTX 590 card's with two 8 pin pci-e supplementary connectors in known to pull over 400W under full load.
You get what you pay for - don't cheap out where it counts
I'd go for the XFX
You can exceed it and with a good PSU, there will be no issue however extra load will be put on the PSU causing it to deteriorate much faster. The 7970 however probably won't ever exceed 350W.
Well in that case, go for the XFX unit because you won't find much - if at all anything higher quality than that in your price range. If you wanted however you could get a higher wattage XFX (850W) for around £80 from amazon.
Thanks for calculating this ... but .... overclocked max load power consumption of a 7970 is 225W (For the Ghz edition).....
I know I was worng at first, but I did my research and found out, that every chip or rather every card from every manufacturer actually has different watts ..... pretty confusing.... but everything should be in the same range.
So if you take the chipwise 225W and give it a possible vector of 25W+/- you should be totally fine, even if you custom-watercool the cards and push them to the absolute extremes.
Here is a small comparison chart for power consumptions in idle and load.
http://www.3dcenter.org/artikel/stromverbrauch-aktueller-und-vergangener-grafikkarten
The website is in german, but i guess the chart shouldn't post any problem to anyone.
+1 XFX - check my profile, I have the same. Great unit over the last 2 years. Has a 5yr warranty. Very strong single 12v rail. & its rebadged seasonic as previously mentioned.