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With a new R9 280X arriving soon I think now is prime time to get that new PSU I've been in dire need of. It's been 5 or 6 years since I bought my most recent PSU. This poor Antect Earthwatts 650w PSU has been through 3 major overhauls and many thousands of hours of games over that time (I can promise MechWarrior Online accounts for a few thousand alone). I think now is the time to retire the best PSU I've ever had the pleasure of owning. So now we come to the good bits.

I originally was not expecting a new addition to my computing family so I had picked out a Corsair HX650. http://www.newegg.com/Product/Product.aspx?Item=N82E16817139012

But now I think I'll need a bit more oomph to push my overclocked CPU /and/ 2x R9 280Xs So I've altered the list to these 3 PSUs.

Seasonic S12G-750 http://www.newegg.com/Product/Product.aspx?Item=N82E16817151138

Seasonic G-750 SSR-750RM http://www.newegg.com/Product/Product.aspx?Item=N82E16817151132

Corsair HX750 http://www.newegg.com/Product/Product.aspx?Item=N82E16817139010

I've never owned a Seasonic PSU so I don't know their model scheme too well and I'm open to any other suggestions you guys have.

EDIT: I guess I should post exactly what my computer has in it

Intel i5 2500k @ 4.8Ghz
ASRock Z77 Extreme4
8Gb G.Skill Sniper 1600Mhz
AMD R9 280x From HiS @ 1200Mhz
AMD R9 280x From Sapphire <-------The new addition from http://techreport.com/forums/viewtopic.php?f=3&t=95318
80GB Intel 320 SSD
64GB Corsair Nova SSD
1.5TB Seagate Barracuda
Antec Earthwatts 650w
Corsair 400R <------------------ Please note my case. Its' going to require some long cables as my 6-pin connector is at the Top Left of the motherboard!
Cooler Master Hyper 212 EVO
Logitech G500s
Corsair K70 w/ CherryMX Blues
Razer Nostromo

I bought a Corsair and it has been working well for me. I can't say anything more about it than that.

I typed your parts into Newegg's PSU recommender, and it says you need something with 1575 watts! That doesn't seem realistic. But Asus's calculator says you should have 1150 watts. Hmm. Maybe it is still overkill, but maybe 750 isn't going to cut it, especially with your overclocked processor. Some forum posts are saying 850+ watts, but maybe those are guesses too.

Can someone with Crossfire experience chime in? I've never built such a system.

I own a Seasonic X-750 and a P-860 and they are great. It's not a cheap brand but you do get great construction quality and solid specifications. The only negative I can think of, if I absolutely have to, is that the 12V rails are separate and therefore have individual current limits. So, you if overclocking heavily (over the 8-pin connector specs, for example), you can hit the current limit on a rail before hitting the power output of the unit.

Anyway, the G-750 you linked is a good product and I would choose it (or the P-750, if you can afford it) without hesitation.

I can't speak of Corsair, but it certainly is a reputable brand.

Milo Burke wrote:

I bought a Corsair and it has been working well for me. I can't say anything more about it than that.

I typed your parts into Newegg's PSU recommender, and it says you need something with 1575 watts! That doesn't seem realistic. But Asus's calculator says you should have 1150 watts. Hmm. Maybe it is still overkill, but maybe 750 isn't going to cut it, especially with your overclocked processor. Some forum posts are saying 850+ watts, but maybe those are guesses too.

Can someone with Crossfire experience chime in? I've never built such a system.

I used http://extreme.outervision.com/PSUEngine And it shows a 650w as a minimum but recommends 701w. Again input from others will help me determine if I need to up-size even more.

ptsant wrote:

I own a Seasonic X-750 and a P-860 and they are great. It's not a cheap brand but you do get great construction quality and solid specifications. The only negative I can think of, if I absolutely have to, is that the 12V rails are separate and therefore have individual current limits. So, you if overclocking heavily (over the 8-pin connector specs, for example), you can hit the current limit on a rail before hitting the power output of the unit.

Anyway, the G-750 you linked is a good product and I would choose it (or the P-750, if you can afford it) without hesitation.

I can't speak of Corsair, but it certainly is a reputable brand.

How are the cable lengths? newegg isn't showing the lengths of te cables and that is going to be a big deal breaker for me on a PSU.

Milo Burke wrote:

I bought a Corsair and it has been working well for me. I can't say anything more about it than that.

I typed your parts into Newegg's PSU recommender, and it says you need something with 1575 watts! That doesn't seem realistic. But Asus's calculator says you should have 1150 watts. Hmm. Maybe it is still overkill, but maybe 750 isn't going to cut it, especially with your overclocked processor. Some forum posts are saying 850+ watts, but maybe those are guesses too.

Can someone with Crossfire experience chime in? I've never built such a system.

I've ran 2x280X without any overclock and saw ~630W at the wall, ie about 550W PSU output (for a platinum PSU), so a 750W PSU is certainly enough if you are conservative. If you plan to overclock, a 850W PSU should allow approximately a +100W margin for each GPU and the CPU but forget a 3rd GPU. A 1000W would be overkill for 2xGPUs if you're not into nitrogen or custom watercooling.

Anyway, wattage is not a substitute for quality. Get the best quality you can afford at 850W and you should be OK.

Ptsant, thanks for bringing your experience.

Anyway, wattage is not a substitute for quality. Get the best quality you can afford at 850W and you should be OK.

Philldoe, there is your answer.

ptsant wrote:

Milo Burke wrote:

I bought a Corsair and it has been working well for me. I can't say anything more about it than that.

I typed your parts into Newegg's PSU recommender, and it says you need something with 1575 watts! That doesn't seem realistic. But Asus's calculator says you should have 1150 watts. Hmm. Maybe it is still overkill, but maybe 750 isn't going to cut it, especially with your overclocked processor. Some forum posts are saying 850+ watts, but maybe those are guesses too.

Can someone with Crossfire experience chime in? I've never built such a system.

I've ran 2x280X without any overclock and saw ~630W at the wall, ie about 550W PSU output (for a platinum PSU), so a 750W PSU is certainly enough if you are conservative. If you plan to overclock, a 850W PSU should allow approximately a +100W margin for each GPU and the CPU but forget a 3rd GPU. A 1000W would be overkill for 2xGPUs if you're not into nitrogen or custom watercooling.

Anyway, wattage is not a substitute for quality. Get the best quality you can afford at 850W and you should be OK.

Just caught a great deal on an HX850 that's ending today. http://www.newegg.com/Product/Product.aspx?Item=N82E16817139011

Bought it for 129.99 with the provided promo-code. Thanks for the help guys!

Nice! Post benchmarks when you get your new card.

The Corsair power supply that you've selected should be more than adequate. I have this SeaSonic PSU, which has occasionally been offered for as little as $100 -20MIR.

Well that was quick... 3 day shipping seems to mean 12 hour shipping.

I am glad you went with a 850 watt PSU over the 750 watt PSU.

My just about 4 year old Corsair 850tx is going strong and it has no problem running my 2600kOC along with my 770 classifieds in SLI. I much prefer a good 30% extra wattage over what is needed then just enough wattage. It sure has worked out well for me since the 90's since I never had a PSU fail.

Watch with my luck my computer will now burst into flames!!!

With all of this happening I may have to start looking into a better display setup. Most of the time I run games at 1080p on a 42" LG TV that...I'm amazed to say... has every bit the image quality of a 23" IPS Asus display I put into a recent build for a Canadian friend. Crossfire will be wasted on such a low resolution, but I do have 2 other 1080p displays that I can shove into eyefinity for now. I think my next stop is to find a 4k display that's as good as my current 1080p display...and the same size.

I think 4k is overated....get yourself a nice 34" 21:9 LG superwide 3440-1440 IPS monitor LGUM95 is the model #. It is only 2.4 times the pixels of 1080p not the overkill 4x 1080p.

I am sure everyone with a 27" 2560/1440 monitor will tell you they are plenty happy with the pixels per inch.

Anyway that is the monitor i want to Buy myself.

vargis14 wrote:

I think 4k is overated....get yourself a nice 34" 21:9 LG superwide 3440-1440 IPS monitor LGUM95 is the model #. It is only 2.4 times the pixels of 1080p not the overkill 4x 1080p.

I am sure everyone with a 27" 2560/1440 monitor will tell you they are plenty happy with the pixels per inch.

Anyway that is the monitor i want to Buy myself.

See, I've been spoiled by this giant LG TV. It has the sharpness I expect from an ISP panel, and it's so massive I feel that I can almost see single pixils move, which has been a massive boon for my competitive play in MWO. Maybe I just need to buy 2 more of these and run them in eyefinity. Then again buying 2 more would cost more than a good 4k display. This TV wasn't cheap.

Let me be the first to say that those online calculators are usually bogus. Unless its asking for 100 specific parts and even then I've seen them suggest jusy shy of 1000w PSU's for a simple i7 build with 1 drive, one mid grade video card and 2 RAM dimms. So don't put a bunch of stock in them.

Id highly suggest the HX750 as it is a solid supply, quality parts, damn good warranty and Corsair's excellent customer service if you ever need it (not likely). I've used about 7 or 8 of that exact supply in server/workstation builds. They are solid performers and havent had anything wrong with them as of yet in machines that are on 24/7 powering 4-6 enterprise drives.

If you want to pinch some pennies the RM750 can be had for just 119.99 on amazon. Its a slightly less version of the HX and carries a lesser warranty, still good supplies from my knowledge.

Holy thread necro batman. Uh yeah, I ended up buying a Corsair HX850. It's been running great since august.