6990 Crossfire MAJOR problem. Please help.

I just wanted to make sure that I've placed my two 6990s in the corrected slots on my motherboard.


I have inserted 1 6990 on the top pci slot (bottom left, top red slot with a battery directly below it) and another 6990 in the slot two below it.

I did this to maximise air flow as the 6990 in the first slot was getting very hot due to lack of airflow.

Is the positioning correct?

Also, in some games, I get a higher performance when CF is disabled. I have posted two videos on YouTube. Of the same game, with and without CF enabled and I got a higher fps, why is this!? The computer is detecting 2 6990s.

Crossfire http://www.youtube.com/watch?v=d5_IJWCRCjY
Crossfire disabled http://www.youtube.com/watch?v=Cwbajpd7xE8

The specs of my machine are in the YouTube video.

I know this is a long question, but I really need help as I believe that I may have wasted a lot of money on a second gpu.

Thank you.
24 answers Last reply
More about 6990 crossfire major problem help
  1. What slots does the Maximus II extreme motherboard tell you run in it? I doubt it but maybe the slot you chose makes it run in x4, not x8. Read your motherboard manual to clarify.

    Also are you running multiple monitors? If not you don't need two 6990s what so ever...
  2. How do I check which slot they're in? I've flipped through the manual many times and I have to say that it's pretty poor.

    I am achieving an fps of only 25 in some games, including the videos that I posted (only sometimes) therefore, it looks as though I do need them.
  3. No you don't need them. There has to be another reason for your problems.

    What resolution are you running. Is your CPU overclocked. How many monitors do you have? What drivers are you using? What programs are you running besides your game? Do you only experience problems while recording gameplay? Does it only happen in Rift, or every game.

    These are all important in determining the problem.
  4. I am using the latest drivers. A single 22" samsung monitor at 1680x1050 and the CPU is not overclocked. When playing any game, my CPU isnt even using 1/4 of it's power.
  5. Uhm.... yeah at that resolution you can max out that game easy with just a 6950. And your CPU only uses 1/4 of its power becuase I'm sure that game only utilizes two cores. Try overclocking the CPU, if you spent that much money on a computer I hope you bought an aftermarket cooler for that CPU, you should be able to get 4~ Ghz easy on that chip.
  6. My fps is only extremely low in rift. however, in crysis, there was quite a lot of tearing, especially the ocean. The graphics didn't even look that stunning. Also, in the 3dmark vantage test, there was a bjt of tearing in that too. Also, the unigine heaven benchmark was quite laggy even though it was at 120 fps with vsync enabled. Finally, during the Final Fantasy XIV benchmark, there were sudden dips of very low performance, only for about half a second, but it was very annoying.
  7. I haven't purchased an aftermarket cooler, which would you recommend?
  8. Are you talking about screen tearing? Thats becuase you have WAY too much horsepower and FPS, turn on Vsync to stop that.

    Don't worry about FFXIV bechmark, unless they have changed that it runs in windowed mode and thusly only uses one GPU (and you have four).

    Do you have like AA and AF enabled all the way max? If so disable those down.. even with amazing cards those get extremely taxing (and show no visual improvement past like 4x AA).

    Also at such a low resolution your CPU has to work harder, that is why it needs to be overclocked.

    What do you mean by laggy at 120 FPS? I don't see how it can be laggy, can you explain better.

    If you really want to stick with that resolution can you return on of the 6990s you do not need two at that resolution at all.

    Finally are you absolutly sure your drivers are up to date?

    EDIT - Give me a sec, I'm reading your motherboard manual.

    EDIT 2 - It doesn't seem like your read your motherboard manual clearly at all. Check out page 2-14, and 2-15, granted it "sounds" like you have them in the right slights, but I'm not sure. You'll have to compare.
  9. I meant laggy as in, stuttery. The camera movement wasn't fluid like it should have been at 120fps and it looked as though it was running at 12fps. Yes I am pretty sure as I downloaded the whole suite from the ati website yesterday and the drivers were released a few days before that.

    I built the computer from scratch yesterday and it was my first build.

    Alright, thanks a lot :-)
  10. Ah, maybe the second gpu is in the wrong slot? The manual says that 4 is a pciex 8 slot. Not a x16 slot.
  11. Well check out those pages in your motherboard manual. Make sure the cards are in the right spots.

    Do you have a 120Hz monitor or 60?

    No matter what the situation... the gameplay in those videos you showed me looks fluid, being an online game it might just be lag, or as I said earlier you mgiht have your AA and AF at rating way to higher.

    I would quickly get money back on that second card, and use that money to get a 1920x1200 monitor, or a 2560x1600 monitor.

    Lastly with that computer it would be a shame to not put an aftermarket cooler on the CPU and overclock it.
  12. Yes my AA and AF were at max. Also, I meant the unigine heaven benchmark wasn't fluid. Which aftermarkte cooler would you recommend? (one which is very easy to install)
  13. Oh and my monitor is a 60hz monitor.

    EDIT Do you know of a good 120hz monitor 24"+ for under $500?
  14. They all take about about the same requirments to install... Here is a list of some of the better ones...

    NH-C14, Tower 120 Extreme, NH-D14, Thermax Eclipse II, Frio, CNPS9900 Max, Magahalem, Iceage 120 Boss II, TTC-NK85TZ, Vapor 120, Corator DS, BADA, or Silver Arrow

    Turn your AA and AF down... see if that helps you.
  15. oh yah man your waaaaaayyyy off .....the slot you want to put it in is in MY motherboard!!!.... all jokes aside one of those will be more than enough for any game maxxed out for at least a year or two......and yes it wants to be in either the first or third slot for x16 bandwidth....and i cant stress this enough ...do not overclock on a stock intel heatsink....the noctua is the best the other guy listed cant go wrong with that.....and lastly amd actually runs smoother on higher resolutions crank em all to the max....itll run smoother
  16. Alright thanks, how should I over clock the CPU, via the bios or a system utility? Also how much should I OC it by?
  17. badtaylorx said:
    oh yah man your waaaaaayyyy off .....the slot you want to put it in is in MY motherboard!!!.... all jokes aside one of those will be more than enough for any game maxxed out for at least a year or two

    Especially at his resolution....

    Which means there is an error in something somewhere.

    As I said I would start off returning one of them and getting a better monitor.

    Deffinitly OC it via the BIOS. You can get really high on those chips, but around 4-4.5Ghz would be nice and would stop a lot of the CPU bottlenecking.
  18. badtaylorx said:
    oh yah man your waaaaaayyyy off .....the slot you want to put it in is in MY motherboard!!!.... all jokes aside one of those will be more than enough for any game maxxed out for at least a year or two

    Haha, I missed by quite a bit then! :p

    It's too late now anyway, if I open the box the company I bought it from doesn't take it back. at least it'll keep me future proof for 3-4 years :/.

    I think I'll just get a 24" 120hz ASUS monitor as I heard those are good value and quality. What do you think?
  19. javilionaire said:
    Haha, I missed by quite a bit then! :p

    It's too late now anyway, if I open the box the company I bought it from doesn't take it back. at least it'll keep me future proof for 3-4 years :/.

    I think I'll just get a 24" 120hz ASUS monitor as I heard those are good value and quality. What do you think?

    Well it would deffnintely let your GPU strech its legs a bit more, and from personal experience the more resolution the better for MMOS, more spots to put GUI bars and what not.

    Granted you could get a 2560x1600 monitor and still be fine with those GPUs.

    Something is faulty software wise I think... tI maybe becuase of the resolution and stock CPU giving you problems but I can't imagine that would be it... I'm very "key" on CPU bottlenecks and even though its at stock the 2600K is still a beast.

    Hey my computer runs Rift at 1920x1200... wanna trade? XD :lol:

    All jokes aside.. I think before you buy monitor it would be better to try and see if you can't fix the problem (you should still buy a new cooler for that CPU regardless of what you are doing or plan to do).

    There is no harm in getting a new monitor, it would increase your gaming experience, but it isn't going to fix what ever problems you are having.
  20. Hehe, I have no idea what the problem is, but I'll get the new cooler, OC the CPU, which may fix it, and update you within the next week so subscribe :)

    EDIT - I do have a strong feeling that my monitor is the culprit. It is quite old and the overall quality of the monitor is pretty poor.
  21. Just make a new post when that happens. Hit me up with a PM (write down my name or something) when you make it, and I'll check.

    I don't think a new monitor and a CPU OC are going to fix your problem, but they deffinitely can't hurt. It would be much more benefitial to try and solve the software problem. Which I think it could be.
  22. A couple notes, first I'm not sure Rift supports quad X-Fire, which would explain why using both cards lowers your FPS. (Also quad X-Fire eats a bunch of CPU, though your videos don't look like they'd be CPU limited)

    What I'm more curious about is your FPS during zone invasion events. The FPS running around Meridian and such really doesn't matter much. If you can still maintain 30+ FPS in a Stillmoor or Shimmersand zone event at maxed settings then I'd call it good. Also you have AA set to Supersampling, which I know people have said flat out halves their FPS in Rift depending on the card. (though on an Nvidia card I didnt notice near that much drop). Try changing it to edge smoothing and see what your FPS is.

    Honestly Craigslisting, or obeying one of your 6990's and buying a 30" monitor would vastly improve your gameplay experience though. I have a 32" 1080p TV I used as a monitor for playing rift, and it's very nice. (even with much less horsepower to drive it than what you'd have)

    In general Quad X-Fire/SLI doesn't work well with many games. Very rarely is their optimization for more than 3 GPU's, just because such a setup is so rare. And as you see, in bad cases you can actually lose performance. I would be curious what your performance is like comparatively using 3 of your 4 GPU's actually. It might be worth testing.
  23. To start, if you want decent performance, turn off supersampling :P

    Also, a lot of games don't work properly with multiple gpus at all, let alone four. You should probably start by looking into if Rift is in fact supposed to use them correctly.

    Also I hope you're testing fps outside of fraps, as using cpu on that entirely contaminates your findings. And you should be looking the exact same situation/benchmark while testing, or at least as close as you can get it. In games like that, even one character on the screen can make a huge difference. Also, those games are fairly notorious for being cpu limited, especially in large crowds. That could also be your issue here.

    So it seems like other games/benchmarks indeed scale properly? Then all signs would post to issues in Rift, and not the graphics cards.

    As far as screen tearing, you will see more tearing if you're running things above your monitor's refresh rate. If you have a setup like that, I would absolutely recommend a 120hz monitor, both to minimize tearing and for the amazing benefits you'd have, both in desktop situations and for games with that ridiculous graphics horsepower.
  24. QuadFire/QuadSLI have a lot of overhead. This is why they often lose to setups with less GPUs at relatively low resolutions. Only at very high resolutions like 2560x1200 or higher when lesser setups start being pushed into a performance wall, Quad setups start showing advantages.
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