SOLVED Dual PSU's, what are the risk?

ok so ive finally convinced my gf to allow me to build my dream machine, which will have 4 gtx 680 4gb cards aswell as a custom loop, a few HDDs/SDDs, br burner etc, and the 4 GPUs alone require 1200w, so im doing dual 1250w ocz zx's, i kno how to make them both boot at start up and all that (making my own lian-li style adapter, aswell as all my other cables) and i was wondering what are all the risk im running by doing dual PSUs?

im going to be splitting the load as evenly as possible over the 2 supplies, and yes i kno im gonna have a few hundred extra watts, but id rather have extra power than risking underpower.

i havent decided on what all my LCS will include except that itll cool my 4 gpus and cpu, and will b running at least a 4x120 rad, and a 120 rad. and a third rad depending on room limitations with the second PSU.

if you need any more info ill give you what i can, but i mostly just need to kno what im risking by having dual PSUs, and i was told that even tho theyre twin PSUs they could b running at 12.1v and 12.4v, just as an example, so what threshold should i switch out a PSU for if theyre opperating at a too-wide of a psread in voltage?

Those GPUs aren't 1200W total, maybe more around 1000W-1100W. You should be able to run it on a single 1500W.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817256054&name=Power-Supplies
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story5&reid=175

Also a good 1600W unit:
http://www.newegg.com/Product/Produ...na-_-na-_-na&AID=10440897&PID=3891137&SID=KRB
http://www.hardocp.com/article/2012/06/11/lepa_g_series_1600w_power_supply_review/9


You're going to need WAY more raddage than that, btw.

Don't forget the screens/keyboard to back up a build of this caliber.

Properly wired there isn't much in the way of risk really.
Are you planning on OCing a lot? I ask because four GTX680s is ~800w at stock. They're a 200w TDP. If you're planning to OC heavily that does go out the window, but it takes a pretty heavy OC to make a GTX680 eat 300w.
I would be inclined to get a single beefy PSU, but that's just me.
If you're going dual you don't need anything close to dual 1250w units, 2500w for a rig that might just barely hit 1500w OC'd is a bit much!
What CPU(s) are you planning on?

Mismatched voltage wise, GPUs have each input isolated from all the others so they don't care. A motherboard with two CPU power connectors could be awkward, I would make all the connections to the motherboard from a single PSU.

If you're set on dual PSUs, I would get two of one of these two:
Seasonic Platinum 1000w
Kingwin 1000w Platinum
2000w is well more than enough and they both cost right about the same as the OCZ and are better units.

The asus psu calc came up with the 1200w for the 4 gpu's, i thought it seemed high but wasnt sure. And i am gonna b OCing alot once i get my lcs built, but not before then.

Ill b running an i7 3930k with a rampage iv extreme mobo by asus.

Is ocz a bad choice for PSUs? Ive always bought ocz and have had really good experience with them.

You're going to need WAY more raddage than that, btw.

Don't forget the screens/keyboard to back up a build of this caliber.

Click to expand...

i currently have triple 21" but i plan on upgrading those with this build, my mouse is a cyborg mmo 7 and im getting a cyborg strike 7 keyboard, which i plan on doing a white mod job too to match my build.

and what type of raddage do u think i need? ive nvr built a LCS before

Pretty much all PSU calculators overestimate by a lot. The GTX680 is 200W at stock, the 3930K is 120W. Everything else might draw about 50-60W. You're looking at about 1000W stock. 1500W is more than adequate for overclocking.

This tells you how to figure out how much raddage you need: http://www.overclockers.com/guide-deltat-water-cooling/

Sweet ty for the links, thinking bout goin with the lepa 1600w, its sexy, and i like the pcie cables, ill b making my own, but ill b mimicing the stock setup for them.

Im gonna mark this solved.

Do keep in mind that most US power wiring is only rated for 15a, which may not be enough for the computer to share with anything else. You'll probably want a dedicated circuit for that thing if you start OCing