SLI queries

[PixelChef]

Hi,

I plan on upgrading to SLI, as I want a 3rd monitor, I have 2 QNIX 2710's (1440p), and I want another But I have some questions as I haven't used SLI before.

So first thing's first, I'm looking for a 2nd hand SLI motherboard on the MM, but if I can't find a decent deal I was looking at this: https://www.overclockers.co.uk/showproduct.php?prodid=MB-279-MS&groupid=701&catid=5&subcat=2811

Any other suggestions?

My card is a GTX 770 4GB, do I have to get another 4GB version or will a 2GB version work too? Also, I assume x2 770's will be enough for 3x 1440p monitors?

Last question (I think), will I need a new PSU? I have a SuperFlower Leadex GOLD 650W Fully Modular PSU.

Thanks!

 

[PixelChef]

You'll want a 4GB one yes and a new PSU (I think 650w is pretty close to the bone, especially if it's a older)

As for how it will play - I have just the one QNIX and I find 1x970 to be just about sufficient for the more demanding games. Before that I had 670 SLI (2GB) and that was about the same performance if RAM wasn't a consideration (which it is these days). For 3x1440p you'd need more than 770 SLI on modern games.

As above you'll need 4gb version as SLI memory mirrors , if you wack a 2gb version in , you will,be limited to 2gb usage . 650w is cutting it abit fine however , it's a quality unit and unlikely to get better at that range . I would personally think they would be fine , what's the rest of your system ? Anything overclocked ? As that would be the deciding factor . i wouldn't however use two of those to power 3x 1440p monitors not unless your seriously prepared to except a massive hit in framrate and fidelity all for the sake of resolution

Okay thanks I will look for a 770 4GB version. Don't mind too much if I can't play games maxed out, I can max out Crysis 3 on a single 1440p monitor with a single 770 so I think should be fine. Worst comes to worst I can always just game on single monitor if it can't handle it.

Full system:

Qnix QX2710 @ 2650x1440 @ 115Hz
i5 4670k /w Corsair Hydro H80 Liquid Cooler
Nvidia Geforce GTX 770 4Gb
8GB DDR3 2400MHz
Gigabyte Z87-D3HP
Samsung 840 250GB
ASUS Xonar D2
Win7 64bit
SuperFlower Leadex GOLD 650W Fully Modular PSU
Fractal Design Define R5

I hope the PSU will be enough. Nothing is overclocked really.

I have purchased a Z97X-UD5H-BK to replace the mobo.

Also maybe worth noting I have 4 HDD's

Oh and one last question, can the 770 4GB be a different model? Or does it have to be exactly the same card?

 

[PixelChef]

Don't want to sound churlish, but you must be happy playing at less than 30 frames per second then?
I currently run 780Ti's in SLI, at 1440p, and they can just about 'max out' crysis 3 and stay above 60fps all of the time.

We can all max out games - the framerate/ performance has to go along hand in hand though to make it worthwhile

Well yeah certainly don't get 60 fps but it's not too bad, and when I say maxed out I don't mean literally, I think I had all settings on max but with AA off and it was playable. I'm happy to turn a few settings down.

Can be any manufacturer of 4gb 770.

Thanks.

 

[PixelChef]

I may need a little advice here.

Since making this thread I've been waiting for a 2nd hand GTX 770 4GB to come up, but no luck. So I'm giving up and decided to try and get x2 GTX 970's instead, however my friend advised me that there is an issue with memory for 970's in SLI and it might not be enough for the resolution I want to use.

Would two R9 390's in crossfire be a better option? Only issue then is if my PSU would be enough. (See OP)

Anyone?

 

[PixelChef]

Thanks for the replies. It would probably be easier and better to get a single 980ti, but the main reason I need SLI or crossfire is because the 3 monitors I want to run only have DVI and not HDMI, so I won't be able to connect 3 of them to a single card unfortunately (unless it's possible with some kinda adapters, will have to look into that)

Any opinions on 970 SLI vs R9 390 xfire?

 

[PixelChef]

The G1 980Ti has 2xDVI, you could use a cable with DVI on one end and HDMI on the other with the 3rd monitor. Seen quite a few reports of this card giving coil whine though, so you would hope to be lucky and not get a whiner.

https://www.overclockers.co.uk/showproduct.php?prodid=GX-164-GI&groupid=701&catid=1914&subcat=1402

With two 970s you will find quicker dual card support on the many new Gameworks games that are released. If you are not bothered about waiting weeks or a month+ for dual card support on new games this doesn't matter. The 970s are much less suited to your very high resolution than 390s. Many users will chip in saying 970 SLI was great, even though it's unlikely they would have used 3x1440p. They probably wouldn't still be owning the 970s if they did.

For me, when I had the 295x2, the Witcher 3 came out and it was at least two weeks before a crossfire profile was released. I would rather have a single high end card working all the time, than a slightly more powerful combination that relies on software, which is sometimes not there on new releases.

I initially replaced my SLI 970's with crossfire 8Gb 290X's. They ran hotter than the sun and I replaced them with a single 980 after about 10 days.
I know it's not 390's but aren't they similar cards?

I think I'm decided on the 390 xfire.

It's a shame I can't just use one 980ti, but I need 3 DVI ports to support overclocking on the monitor, if you didn't know these monitors at 60hz but you can run them at up to 120hz, but this requires a DVI port.

I'm not too bothered about having to wait a little while for crossfire support, as I rarely buy new game releases these days anyway. Also from the reviews I've read the 390 seems quite quiet and cool?

Only question now is, whether my PSU is enough for 390 xfire: SuperFlower Leadex GOLD 650W Fully Modular PSU.