As you may know, multi-GPU setups can often face issues that do not exist on single GPU setups.

Let's use this topic here to share tips, tweaks, settings, applications used, profiles that worked for troublesome games (CFX), SLI bits (for SLI), rendering modes (AFR / SFR / SuperTiling), etc... so we can benefit from each other and have a better multi-GPU experience.
My spec is
I5 3570 @ 4.2 Ghz
Corsair 8GB 2000 Mhz
2x Sapphire 7950 Vapor X (11196-09-40G) 2x8 pin version (950/1250 stock)
CM 1000W psu 80 plus silver
CM HAFX case



Don't comment on the cable management because this was an early pic when I just installed them :p
I haven't done much with them lately except some gaming and some heaven benchmarks because of my schedule. But I'm willing to play with them when I have the chance.

I'm using Msi Afterburner @ 1000/1375 clocks and stock voltages ofc(1125mV) stock Fan control. Temps go max to 60 deg (top card) in most demanding games like crysis 3 but normally it is in my 50's .(As a side note, I am not using the HAFX VGA fan duct(don't think it fits) or the VGA Holder(doesn't fit at all because my cards are monstrously huge ) ).
Also for who's interested, the cards are amazingly silent and cool. That's one of the reasons I didn't mind OCing even with high fan profile.

I don't see any reason to OC them tbh since It is topping all the games I'm playing but who am I kidding, I can't just leave them at stock.
I am not experiencing any stutter issues at ALL and gaming is buttery smooth as long as I am capped at 55-60 fps. I'm using Radeonpro profiles for each game and doing the following ( In Tweaks Tab :: Vsync Control :Always on (Double Vsync) -Tripple buffering on- Dynamic Frame Rate Control on- keep up to 60 FPS) Although I got a slight issue that I'm planning to fix with Crysis 3 when the FPS dips below 60, it stutters just a tiny bit but I like my games polished.


Anyhow, I got 1650-64.8fps score in heaven 4.0 with max setting@1080p (8xAA Ultra quality and extreme tesselation) I think that's normal and nothing is bottlenecking in my system.(compared to what I've seen online)

I'm open for all suggestion and tips since this is as far as I got knowledge and experience wise. And one more thing... SHOW ME YOUR STUFF!!
AWESOME! So it's running as we went about it last time.

You do not need to enable Triple Buffering for CrossFire, since CFX inherently uses something similar to Triple Buffering when running AFR.

I don't think you need Dynamic Frame Rate Control since when you dip below 60FPS, even with VSync on, you don't go directly to 30FPS.

Other than that, that's to be expected from Crysis 3, especially when you raise AA, as that game brings even my 7970 down to its knees. Make sure you run the latest Catalyst 13.3 Beta 3, as it includes improvements for Crysis 3 (maybe especially CrossFire). Some OC and it should run at a smooth 60FPS I suspect. Also, check if your cards are at 99% GPU usage when you dip below 60FPS.

I can't show you my stuff now, things are a mess :( I burnt a VRM on one of my 7970s on December 31. Now I ordered replacement VRMs after I FINALLY found out what those things were, and they should be here in like two weeks or so.

Anyways, for the primary card, I'm getting heatsinks this week, so it's going to be on water. I'll share my experience over on the other topic.

Share some scores on the other topic, with screenshots. That Heaven 4.0 score seems on the ball.

You might want to read this: AMD Comments on GPU Stuttering, Offers Driver Roadmap & Perspective on Benchmarking

I'll post some overclocking tips on the other topic now.
Alright Great! , I will try to play with Radeonpro like you said and check the results. I forgot to mention that I'm using the 13.1 driver because the 13.3 is still in beta and I am still in testing phase and don't wanna face driver issues at this point. But I'll consider upgrading.

I'm sorry to hear about that VRM man that sucks :X. I checked my VRM temps and they are cooler than my core temps all the time while benching and gaming.

I will update the other topic with some scores.

Thanks for the help!
11 days later
Hey guys sorry I've been away for a while because my SSD died on me and I'm getting a new one soon.
Zahix wroteHey guys sorry I've been away for a while because my SSD died on me and I'm getting a new one soon.
Darnicles! What SSD was it?
8 days later
Well, tried Crysis 3 on a 7970 CF setup just now. 7970s @ 1125/1375. Crysis 3 maxed out @1080p, 4xMSAA (medium).

I now understand what you mean by those stuttering issues. The game itself is whacko, even on a single card.

You'd be looking at some place and achieving a constant 60FPS, pan to a different view and boom your FPS starts fluctuating like crazy ONLY to settle back at 60FPS! This is CRAZY! And it seems VSync enlarges the effect even more!

This game has mostly minimal / practically no microstutter with VSync off, as it doesn't scale 100%. It scales pretty close though.

This title needs some work with patches and such before it can achieve a constant 60FPS on CF setups. It has problems even on Nvidia cards, like the GTX680. Oh well.

However, it's still pretty much playable, and the FPS difference going from a single card to dual is just MASSIVE.

And finally, something to actually show off these cards' potential.
Are you guys all gaming at 1080p? it's a shame since your setups are way overkill for that.
you can count on 1 hand the number of games that would truly stretch your systems.
I'm on one 670 OCed and i can handle most games maxed out at 1440p. Crysis of course is another story, but only when pushing AA does the game get unplayable. however you'd be surprised how little to no difference AA makes on a higher res monitor.
I guess so, but we can't find any 2560x1440 monitors here.

Plus, it's pretty hard to maintain 60FPS at 1080p with a single card, often even with reduced AA. Thr hit going from 1080p to 2560x1440 on a single card would have us get less than 30FPS minimum. That's less than 60FPS with two cards.

Personally, I wouldn't run 2560x1440 on a less than triple card setup.

Also, I'm very interested in benchmarks on 1440p. Could you show me some benches for min FPS? I'd really appreciate it.
Yes there's an immediate 30%+ hit when you move to the higher resolution, but again let's be honest most games are not demanding, and you don't need the higher level of AA with those monitors.
i think the situation will change once the new gen consoles hit the market, and we see more native DX11 games together with the release of new engines. When that time comes, i might drop in another 670 or get a Maxwell card. (Kepler's replacement).

i'll try and run a benchmark at some point and post the results.
PowerPC wroteYes there's an immediate 30%+ hit when you move to the higher resolution, but again let's be honest most games are not demanding, and you don't need the higher level of AA with those monitors.
i think the situation will change once the new gen consoles hit the market, and we see more native DX11 games together with the release of new engines. When that time comes, i might drop in another 670 or get a Maxwell card. (Kepler's replacement).

i'll try and run a benchmark at some point and post the results.
The 30%+ hit is mostly an average, though. For games that are really demanding, like Metro 2033, the performance hit tends closer to the increase in the amount of pixels being pushed, which is 77.77% when moving from 1920x1080 to 2560x1440 or from 1920x1200 to 2560x1600. So let's say one is bottlenecked at 1080p, the performance hit could be anywhere between 0% and 78% when moving from 1080/1200p to 1440/1600p, except if we run out of VRAM at the higher resolution.

Nevertheless, the Catleaps are amazing, just...amazing, but unfortunately it's not that easy to get them here. Plus, our secondhand market is not very active for graphics cards, else it'd have been easy to just sell a card you have and upgrade. If you keep up with quickly selling before something becomes obsolete, then you'd always have the latest gen cards.

Do you run out of VRAM @1440p with 2GB?

Thank you in advance for running some benches!
yasamoka wroteWell, tried Crysis 3 on a 7970 CF setup just now. 7970s @ 1125/1375. Crysis 3 maxed out @1080p, 4xMSAA (medium).

I now understand what you mean by those stuttering issues. The game itself is whacko, even on a single card.

You'd be looking at some place and achieving a constant 60FPS, pan to a different view and boom your FPS starts fluctuating like crazy ONLY to settle back at 60FPS! This is CRAZY! And it seems VSync enlarges the effect even more!

This game has mostly minimal / practically no microstutter with VSync off, as it doesn't scale 100%. It scales pretty close though.

This title needs some work with patches and such before it can achieve a constant 60FPS on CF setups. It has problems even on Nvidia cards, like the GTX680. Oh well.

However, it's still pretty much playable, and the FPS difference going from a single card to dual is just MASSIVE.

And finally, something to actually show off these cards' potential.

You want me to remove Radeonpro and and Vsync ?? What about tearing ?

I can't play the game because I had it installed on the SSD and now it is not available :(. Most probably I'm gonna end up re-downloading it, on a new SSD that I will buy soon. Any recommendations btw?
Try without VSync, but I don't think it got particularly better for me.

Recommendations for SSDs? If you want local, check out the Intel 330 SSD available at pcandparts and Macrotronics.

Amazon, check out the Intel 520, Vertex 4, Samsung 840 Pro, Crucial C500, etc...
yasamoka wroteSoooo, AMD have just released Catalyst 13.5 Beta 2...

Aaaand Frame Rating: AMD Improves CrossFire with Prototype Driver.

Ummmm-hummm (nods head)!

Aaaand the 7990 is out. Check out some reviews!
Awesome, I'm gonna try and play with Vsync only and check for improvement.

I installed 13.4 with new CAP but my crossfire is not working anymore(2nd card is turned off). I did a clean install with driver sweep. When I disable Crossfire from CCC, the 2nd card turns on but when I turn CF on, it goes off >.> I reinstalled and the problems is the same.

ps :I'm on second bios all the time.

help !
What do you mean by turn off? You mean the fan turns off? If so, that's normal, that's ZeroCore power saving kicking in.

Try to load a game, you'll see the fan spin up and the card's GPU usage goes up normally.

Also, the damned 13.5 Beta 2 drivers are NOT the prototype drivers. So don't bother downloading it if you're merely doing so to test the frame pacing fixes.

Do NOT install 13.5 Beta 2 without fully removing the 13.4 drivers. That was a warning I read.

Seems like we'll get the drivers in the summer. Here's hoping for a leak xD
I mean its Vga LEDs are off... but it looks fine now somehow. Maybe it needed time to adjust after enabling Crossfire.

Too bad, I am really interested in the prototype driver :( I'll stick with 13.4 for now and play with it a bit . Gonna try heaven now with same OC.
I was looking in Gpu-Z and when I was browsing the second card it showed me this.

Edit: It was a glitch. Fixed when I restarted.

Notice the Bus Width and the Bandwidth o.0
7 days later
I asked AMD on twitter when is the prototype driver gonna be released. They replied that there will be a beta for download in June.

/Fuckyeah