SLI - MSI GTX 780 Lightning power requirements

Lankoss · 24 Dec 2015 at 19:53

I bought 2x 780's in todays Boxing day sale which I plan to SLI when I get back from offshore in a couple of weeks. At first I wasn't concerned at all with the power requirements, but after looking at some of the benchmarking I am a little concerned that my PSU will fall a little short. I THINK I will be okay at stock speeds, but if I go to overclock them I'm worried I may draw too much power, although I guess real life gaming situations won't draw anywhere near the power that benchmarking them at 100% will? Below is my specs, I appreciate any comments on if you think I will be okay or not, I am already replacing my case to accomodate the SLI config (something I wanted to do anyway) but buying a 1000W Power supply ontop is getting into the realms of more money that I am happy to part with.

PSU - 850W Corsair HX Series
CPU - Intel i5 4670k overclocked to 4.3GHZ
Cooler - Be Quiet Dark Rock 2 air cooler
Sound Card - ASUS Republic Of Gamers Xonar Phoebus
motherboard - Gigabyte sniper M5 micro ATX Z87
HDD - 480GB Crucial M500 SSD
RAM - 8GB of Corsair Vengeance Pro Series @ 2133MHz
Case - Will be the Corsair Air 540 so 2x 120mm and 1x 140mm fan i think.

And then of course the 2x 780's ontop.

peahead · 24 Dec 2015 at 23:04

That PSU should be fine mate 2 780 in sli pull about 440w maybe a little more in benchmarking plus your cpu which is the other main power draw of around 160w overclocked.

According to nvidia a 800w psu is recommended for 780sli.

foster grant · 24 Dec 2015 at 23:18

I got two of those cards today too...with hope they will fit in my case lol..but I think I'm going to have to remove my sound card though

setter · 25 Dec 2015 at 00:00

Hx 850 is ok as long as you aren't overclocking heavily, ie extra volts on the cards.

Lankoss · 25 Dec 2015 at 15:16

Cheers guys, that's good to know. I wont be over clocking right away no, not until I get a 1440p monitor at least. I'll be playing in 1080p until then so stock levels will handle anything I could possibly throw at them :-)

Lankoss · 25 Dec 2015 at 15:18

foster grant said:
I got two of those cards today too...with hope they will fit in my case lol..but I think I'm going to have to remove my sound card though

What case do you have mate? The cards take up 3 slots, so if that's all you've got you'll defo have to remove your sound card. I'm waiting to see if the Corsair Air 540 comes on sale any where over the Xmas period, i'll order one full price on a couple weeks time if not.

foster grant · 25 Dec 2015 at 23:15

I got a fractal design r4...so i dont think me sound card is gonna fit lol

setter · 25 Dec 2015 at 23:21

Will the card not fit in the small pcie slot above the primary gpu slot?

foster grant · 25 Dec 2015 at 23:26

Well setter it might...I do have the chose of two sound cards my HDX and also my sound blaster z , both have the shroud on them , plus the 780s have that reactor on them too

Sorry to hijack your thread Lankoss

Lankoss · 26 Dec 2015 at 09:13

That's no problem mate, my question was answered yesterday. Just a note, it has come to my attention that the cards we bought where the LE version, something I didn't pick up on before. Are you planning on OC'ing yours? I would be interested to see what you got if you do as I won't be OC'ing mine until I have a 1440p monitor.

foster grant · 26 Dec 2015 at 13:58

No I'm just gonna rum them " out of the box"

savagesam117 · 26 Dec 2015 at 14:01

Lankoss said:
That's no problem mate, my question was answered yesterday. Just a note, it has come to my attention that the cards we bought where the LE version, something I didn't pick up on before. Are you planning on OC'ing yours? I would be interested to see what you got if you do as I won't be OC'ing mine until I have a 1440p monitor.

I had the LE Lightning 290x and it didn't clock anywhere near the proper lightning card but it was still a very respectable overclock.

Enjoy your cards

setter · 26 Dec 2015 at 14:02

From looking through a few old posts of mine from when i was running sli 780. My power use in games with an oc'd 4790k was around 630w total system draw at the wall, this included the 24" 1920x1200 monitor i had back then.

Scania · 26 Dec 2015 at 14:05

I have a Corsair HX850 powering two GTX580's in SLI (sure they consume more than the 780's) along with an overclocked i7 870, five hard drives (two SSD) an Asus Xonar soundcard and numerous peripherals plugged into the USB ports.

I'm sure I'm pushing my psu beyond where it should be but must say I've had no issues whatsoever with it, it stays cool too.
I'm sure you'll be fine with yours.

Rroff · 26 Dec 2015 at 14:07

PSU should be fine - I specced a 860watt just incase I wanted to go SLI with my 780 but never did - perfect amount of headroom.

setter · 26 Dec 2015 at 14:13

Rroff said:
PSU should be fine - I specced a 860watt just incase I wanted to go SLI with my 780 but never did - perfect amount of headroom.

Mine were ran most of the time i had them on a 6 year old HX850. Later the superflower in sig. Only swapped to it as i got it cheap and it allowed a bit more headroom for overclocking.

foster grant · 26 Dec 2015 at 14:27

And unless I can get a sound card to fit i might just send the cards back

Scania · 26 Dec 2015 at 14:39

foster grant said:
And unless I can get a sound card to fit i might just send the cards back

Had this same problem with my old Creative XFI card, it's slot was obscured by my bottom card (a 3 slot ASUS GTX580 Direct cuII, my top card is a two slot EVGA GTX580) if I fitted the cards the other way around I killed the airflow and had major overheating issues.

Whilst the on board sound was worse than the XFI by some margin the performance boost from SLI made up for it, I've since bought a pic-e Asus Xonar DSX which sits in a pic-e slot above my top card tbh I hadn't even realised my board had one of these slots, the small one rather than a GFX pic-e slot if you will.

The quality of the DSX is far superior to the XFI the only difference I've found is it won't run the sound benchmarks in things like 3D Mark03 which is no loss really!

Have you such a free slot on your board mate?

foster grant · 26 Dec 2015 at 14:52

the two sound cards i have do have those poxy shrouds on them , but i think even if I remove the shroud/s I would still be left with a sound card that wont fit lol...but I'll see when the 780s turn up

TTomax · 26 Dec 2015 at 21:26

Lankoss said:
I bought 2x 780's in todays Boxing day sale which I plan to SLI when I get back from offshore in a couple of weeks. At first I wasn't concerned at all with the power requirements, but after looking at some of the benchmarking I am a little concerned that my PSU will fall a little short. I THINK I will be okay at stock speeds, but if I go to overclock them I'm worried I may draw too much power, although I guess real life gaming situations won't draw anywhere near the power that benchmarking them at 100% will? Below is my specs, I appreciate any comments on if you think I will be okay or not, I am already replacing my case to accomodate the SLI config (something I wanted to do anyway) but buying a 1000W Power supply ontop is getting into the realms of more money that I am happy to part with.

PSU - 850W Corsair HX Series
CPU - Intel i5 4670k overclocked to 4.3GHZ
Cooler - Be Quiet Dark Rock 2 air cooler
Sound Card - ASUS Republic Of Gamers Xonar Phoebus
motherboard - Gigabyte sniper M5 micro ATX Z87
HDD - 480GB Crucial M500 SSD
RAM - 8GB of Corsair Vengeance Pro Series @ 2133MHz
Case - Will be the Corsair Air 540 so 2x 120mm and 1x 140mm fan i think.

And then of course the 2x 780's ontop.

I have the same power supply...Cpu i7 [email protected],and a TitanX SLI on 1500+MHz (with AIO cooling)
No any power issue,the HX850 is a really strong psu.Just keep going,dont buy another one.