Here are the potential system specs for my build, I already have one 780 but I was considering going SLI. As you can see, I have a Corsair AX760i PSU. PC part picker says the build uses 706 watts, but is it actually enough? If it costs me upgrading my PSU I might just wait out on SLI...
Thanks for the help
I would say that is pushing it. One thing to also bear in mind, especially when running SLI, is that PSUs decrease in performance when they go over a certain temperature, usually 40°C - 50°C. Yours looks like a fairly decent PSU though. They also can not always reach their advertized limit, especially under a constant heavy load. They may also decrease in performance over time.
I don't think you will have any issues with that setup unless you max out overclocks on the graphics cards. That is a really solid PSU and can work near it's limit without issue. 780's don't pull an insane amount of wattage maybe 300-400 watts at full tilt; but in SLI that number will be less per card. I would expect you will have no problems over the life of the system as long as you don't over-volt the cards.
Heavy overclocking + stress testing (or dragonage) and you may come close to 700+ watts but if you're conservative enough you'll be just fine. Grab a cheap power consumption meter to test what your system uses if you're at all concerned.
You will be fine. If people say you can't SLI with 750 watt than ask them if they have tried. If they say no then don't take their word on it. Also you are better off getting a EVGA Supernova G2 750 watt. Has the least voltage ripple of anything in its range only very slightly topped but the AX***i series (difference is null). The AX760i is unnecessarily overpriced.
You can run 2x 290X with 750watt. It has been done with head room and overclocked.
I agree with most of that, however, the Corsair is a better unit then the EVGA. The Corsair is better made and more efficient, which is saying alot; as the EVGA is no joke itself. Also you cannot run crossfire 290x's on a 750 watt PSU. I have 290x's in crossfire and I have a wattage meter, it is not uncommon while gaming for that one system to pull over 900 watts. That's in games, synthetics push even farther around 1000-1100 watts. Granted I also have a few peripherals hooked up but still. I would not attempt a 290 or 290x crossfire with less then 1000 watts. While it may work out with some of the best PSU's on the market the power draw on them would surely burn them out. The truth of the matter is the new AMD cards drink the power at a level that is just insane. When you read about a overclocked 290x drawing 600+ watts at load that is no exaggeration.
Corsair only beats EVGA with the HX****i and the AX*****i units. Both of those are priced much higher and the value that you are going to get back is non existent unless you need a perfect power supply for LN2 overclocking. I would not recommend anything of corsairs under the HX**i or the AX***i for the 750/850 watt range when there is the EVGA Supernova G2 line. Its just silly to spend more money when they are about. I still firmly believe that you can crossfire 290X with 850 watt.
May I ask for curiosities sake what voltages you have your 290x's at? And what did you get them to? Did ya break the 1150Mhz mark?
Thanks for the advice, and yeah I love how well made the corsair PSUs are. I'm just a little butthurt because my system only pulls like 450 watts, I feel the need to push it further.
I have 2 290x MSI Lightning cards running at 1100Mhz stock voltages I haven't had the time to really overclock them yet. I know one of the cards is a dud for overclocking yay! for the best 290x made . . . Anyway Needless to say between all the problems with my Mpower which was replaced with an Xpower and the one terrible lightning card I don't buy MSI anymore. The other card however was running at 1150Mhz without voltage increases stable. For crossfire however I just run them at the same clocks.
Yeah, I generally tend to shy away from MSI because they use analogue PWM's.... They have a contract with their manufacturer. Personally prefer digital control because its very tight. Regardless, perhaps send in an RMA request? Its not in good business to advertise a card to overclock well and have it fail. It makes me wonder though how thorough their binning process is...