Anyone know if it'd be possible to SLI these two cards?

I have one of these and was thinking of trying to SLI this other card to it. They're the same 970 4GB cards, but different brands. Not sure on the memory speeds and such, and trying to google the ASUS serial number didn't give me much info. Anyone have any ideas?

HMM

Using 180 or later graphics drivers, NVIDIA graphics cards from different manufacturers can be used together in an SLI configuration. For example, a GeForce XXXGT from manufacturer ABC can be matched with a GeForce XXXGT from manufacturer XYZ.

That would seem to apply?

You should be fine. They both look like 970 4gb cards. If one card has lower memory speeds than the other it'll throttle back the faster so they both are running the same. Good luck on crunching pupflops.

@doctorchimp: @doctorchimp: Cool! Never tried it before. Hope I still have the connector somewhere.

SLI really isn't worth it. You won't get the performance boost you're expecting for most things, and you'll have to do a lot of tinkering to get it to work at all a lot of the time. Expect a lot of headaches. There'll also be a noticeable increase in power consumption. You can probably sell both of them to come close to what you'd need for a new card.

Or just switch one of those 970s with something from an office rig when no one's looking.

The second 970 kind of fell into my lap, so I might as well give it a shot! If it doesn't work out I can always just pop it out.

Yes, you can and it will be totally fine. If the cards have different clock speeds then the faster card will be automatically clocked down to match the slower one.

It'll work just fine, vendor ID isn't factored in.

And by just fine I mean as well as you can expect SLI to work (half the time and variable levels of scaling).

My SLI 1080's give me a massive FPS increase in most modern games, and required zero tinkering.

I think a lot of the old myths about SLI no longer apply. Micro-stutter is rare. Profiles are almost never lacking (just the occasional indie title goes without, but who needs SLI for that?). I've gone through a few generations worth of GPUs with SLI and never have any issues. I can't speak to Crossfire, though. Knowing AMD's drivers, I wouldn't be game to attempt it.

@rorie: A couple of things to be aware of after you install that second card: First, GeForce drivers like to default to Single GPU mode after being updated. The other thing is that sometimes there can be weird driver related issues with SLI that can only be resolved by completely removing the old driver and all settings, then reinstalling from scratch. I recommend DDU.

http://www.guru3d.com/files-details/display-driver-uninstaller-download.html

Anyway just ping me on Slack if you run into any issues, I've been running SLI for years.

Two 970's in SLI should give you around the same performance as a 1080 if you are running a game that scales well. Keep an eye on the temperatures though because the bottom card will get hot. I had to install an extra fan on the side panel to keep the heat in check. I overclocked the cards too though.

I used SLI on my old 760 to give me a boost at a minimal price for a year and a half; just something to improve my quality and framerate until the newest line of cards came out, which it did in the 1000 series. I actually thought of putting off upgrading entirely until I started to notice my SLI wasn't working all the time. Games were coming out without SLI support, either from the developer or NVIDIA. I would have to scour forums and reddit to look for profiles to match just so I could hope to get a consistent FPS. At least half the time it wouldn't work and I'd end up altering some settings and just hoping that maybe if I wasn't paying attention to it, my second GPU was doing something.

I tried it, enjoyed it for a while, and then got burned. I think I'd rather save what little money a second GPU would cost me and put it towards a significant improvement 3-4 years down the line. Unless I get one handed to me or on the real cheap, like in your case Pup-lord.

Well unfortunately it looks like I'm short an extra eight-pin power thingy on my PSU to actually plug this thing in. We'll see!

@rorie:

Are you sure you don't have a connector like the one on the right in this picture? It's a common thing that people miss when looking for the 8 pin connector.

I think my biggest issue running SLI is that some games don't like or support it but rather than not use two it'll instead microstutter to hell or have other issues. I had really bad problems with doom if not single card mode. I know there were others but can't remember which because I don't play games often. For the most part you get better performance with no work, tweaking, fiddling or anything else. Like said though new drivers default to single card so you need to change that when you upgrade.

My EVGA card requires both a six and an eight-pin connector for some reason; guess it's a power hog. I don't have any others in the system as far as I can tell.

@bdead said:

@rorie:

Are you sure you don't have a connector like the one on the right in this picture? It's a common thing that people miss when looking for the 8 pin connector.

@rorie: If you have two spare molex connectors you could get an adapter to eight pin pci-e (they cost about 5$). Also if your power supply is under 700W I wouldn't recommend SLI as you might run into power issues.

I'm just going to bump it up to a Corsair 750w PSU. It looks like it has double the PCI-E connectors as my current setup does. It's about time to get in there and clean out the case anyway, so I figure I might as well.

Also I don't think I have spare molex connectors; I have something like seven drives in the system now and they take up most of those kind of connectors.

A 750w should be fine.

if you have a PSU that is smaller than 750w currently you may not meet the power requirements to run sli with those cards anyway. and as someone mentioned in an earlier post, you might be able to sell both of those 970's and buy a 1070 and get about the same performance if not better, with none of the headache.

I'll find out on Monday when the new PSU gets here I guess! I'd rather just try SLIing these that I have now than bother to try and sell them, but it's nice to have an option I guess.

What motherboard are you going to use?

And I can't find the specs for that card, probably was part of a built system and not sold by itself retail. It would have a nondescript cover without much marketing/branding. So the clock speeds are likely reference GTX 970 spec. You would want to keep your current 970 as the primary in the SLI so that single-GPU workloads use the faster of the two.

Edit: I was doing some more googling and saw a few mentions that OEM 970 cards may not support SLI, so heads-up. I think you should be able to confirm support in the nvidia control panel once you have the card connected. Seems like some OEM cards use a vbios that will only SLI with the exact same OEM card.

If you want to know what card that is it's easy, pop it in a computer.

For the record, this was a pretty easy setup when I got the PSU, although "pretty easy" will vary based on your PC aptitude, I guess. Uninstalled all my video card drivers, unplugged all of the old PSU connectors, switched PSUs, plugged everything back in, plugged in both GPUs, but the bridge on, booted up, installed drivers, SLI was already enabled, and that was that. Not too terrible.

So far the performance increases have been noticeable, especially in Rise of the Tomb Raider and Witcher 3. ROTTR went from 1080p with some stuff turned down to 1440p with almost everything maxed at 60fps on vsync. I don't think I have an FPS counter on Witcher 3 but it looks goddamn gorgeous compared to where it was before, and is also locked to 60fps. The one game that it didn't seem to do much for was Watchdogs 2, but I'll be happy keeping that at 1080p for the meantime, I guess.

I guess I have to play the Witcher 3 now.