Based on the Cooler Master Power supply calculator my total wattage is 677 Watts.
That's with an FX 8350.
Also Lepa is based on Enermax.
I'm sure its going to be fine.
I just slapped together a build real quick for the wattage calculator: http://pcpartpicker.com/p/Lg6zHx
Way too close for my liking.
I have Reference 7950's
Ok after hours of reading up this is what I would recommend for your situation ... just use two of the GPUs in crossfire and save the other as spare ... and use this mobo and CPU and cooler ... meets your budget and gives you backup with the performance of both GPUs at x16 and you will not need a powerhouse of a PSU
http://pcpartpicker.com/p/9yHX23
The 3rd Gpu took a good chunk of my budget..
I didn't buy it to be a spare.
Just being honest with you.
I hope you do know that scaling from 2 way crossfire to 3 way crossfire isn't great.
Since you have them already and intend to use them, here's what I'd suggest:
http://pcpartpicker.com/p/6VhpVn
To help give more breathing room for your power supply, I've gone with Intel. Z97/Z87 is pretty much required for 3 way crossfire, and PCIe 3.0 x4 should be enough bandwidth for each of your cards.
NO OVERCLOCKING PLEASE.
//edit Went with a higher clocked i5 for the same price, but should handle your 3 7950s with ease. It should be a little bit cooler and consume less power as well. Xeon E3-1220 was 4 cores 4 threads. If you want 4 cores 8 threads, step up $50 for the Xeon E3-1231 V3
I'm aware of the scaling.
I have never overclocked gpu's in all my years of owning. Not anything to worry about there.
Only thing I overclock is the cpu and its a small overclock.
Are you certain what you picked out will work ?
Just want to be 100% sure.
Yes, it should work just fine.
Xeons have locked multipliers - you're going to be overclocking with the BCLK. Doing so may cause instabilities as it also interferes with RAM speeds. If you are still going to overclock, consider an aftermarket cooler like a Hyper 212 - the stock cooler good enough only for stock clocks.
Also, what model LEPA power supply do you have? I'd like to check up on it to see if it's any good.
If its going to run games fine on normal clocks I might just keep it like that.
Here's the power supply : http://www.ecomastertek.com/psu_lepa_b850-ma.php
I feel for you .. you probably bought them before the bottom dropped out ... listen to some tech noob ... he is a master tech
VVVVVVV
like I posted earlier ... if you OC those GPUs they will suck the power ... like 411w +/- ? just for GPUs... using the Xeon will help though ... they tend to use less power
Doesn't matter. Really the power usage wouldn't be much different maybe + or - 0 to 5W
The inside isn't an enermax - it's a sirfa design.
Looks like mostly teapo(2nd tier) with some rubycon(1st tier). Not too great build quality. Some noticeable voltage droop, with just average voltage supression.
http://www.hardocp.com/article/2011/06/20/lepa_b_series_850w_power_supply_review/1#.VEiHk_nF8cA
Overall, I'd call it an average and budget power supply. I still believe that you shouldn't overclock with a power supply like this. Games are usually GPU bound - the Xeon should perform just fine in games.
Yeah I wont then.
I don't want it to explode or anything.
I mentioned that I don't Overclock Gpu's.
What kind of case do you have and how many fans?
NZXT Tempest 410 with 7 Fans.
Well that's good.
Why and when did you get these 3 cards?
Its something I always wanted.
Also I plan on doing Surround monitors for gaming.
I already had 2 and ordered one more about a week ago.
You always wanted 3 7950s? Or just more multi GPUs in general or 3 exactly?