HD 5850 in CrossFire not yielding benefits

I've recently installed another HD 5850 into my rig, hoping to improve the performance in Crysis Warhead, but I saw no performance increase at all. I created a benchmark that ran 60FPS with a single card, and that benchmark now runs 53FPS with 2 cards in CrossFire.

I know Crysis isn't a game that scales very well at all, but I thought Crysis Warhead was much improved in SLI and CrossFire performance.

Is there something not right? My 3DMark Vantage scores went from 16500 to 22300 on performance settings, so I know both cards are working.
However, I run the game at 1280x1024 resolution because I have an older monitor, but that still does not explain why I would get LESS FPS with CrossFire.

The second PCI Express slot on my mobo is x4 operation, so I OC'd the card in that slot to 850/1100(725/1000 stock), and the primary card is at 840/1060.

I also tested this in GTA 4, and omfg it's very choppy, not in terms of FPS but it seems like it has to have a 3FPS loading moment everywhere I look before it goes up to 50FPS or so.

Does anyone know if theres something wrong with my setup? or maybe this is how its supposed to be?
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More about 5850 crossfire yielding benefits
  1. There are a few possibilities here. I'll list a few:

    1) Your CPU could be bottlenecking the system in that game. Adding Crossfire to the mix, forces the CPU to work a little harder causing a small decrease in performance.

    2) Your CPU could be bottlenecking the system in that game. Adding a 2nd card put your PCIe slots in x8/x8 mode. Now you also lost a bit of performance due to the loss of PCIe lanes.

    3) You have vsync on. Vsync prevents more than your monitors refresh rate, which is likely 60. You could power it by the worlds most powerful system, but it wouldn't matter, vsync prevents you from displaying more than your monitors refresh rate.

    There are other possibilities...

    With your current resolution, and FPS, you have no reason to have a 2nd 5850. If you plan to upgrade your monitor, it may be useful. What's the rest of your system like?
  2. first of all what are your complete system specs?? Now remember at low res the load is more on your cpu rather than your gpu so you might need to run the game in higher resolution to be able to see much of a benefit, and crysis is taxing as hell, so let me know your full system specs, also the 4X slot is no good, you are definatley taking a hit from that, if you want to run crossfire you should at least have 8x8, I would say sell both cards and upgrade to a more powerful single card such as a 6970 or gtx 570
  3. My system specs are: Phenom II X4 955 - 4x2GB DDR3 1333Mhz - Zalman 9500A CPU fan - Seagate 750GB HDD 7200RPM - Powercolor HD 5850 PCS+ with ASUS EAH5850 DirectCU - MSI 770-G45 mobo - Windows 7 64bit
  4. And yea I hate this mobo, if I can find a good board with TWO x16 PCI Express slots and not a bad price, I would go for it. But the cheapest ones I see like that are about $150.
  5. Best answer
    yeah you will be fine with 8X8 with 5850s just the 4x is garbage but 8x8 with 5850s you will have minimal loss even a 5870 is only reduced by 2-3 percent by an 8x from what I remember. So up to a 5870 level of gpu is fine on an 8x
  6. so if you can find an 8x8 am3 board for a good deal I would go for it.
  7. your system sounds like its got plenty of horsepower for a 5850 crossfire setup, and i see you have a zalman so likely you have oc'ed your 955, I have my 955 at 4.0 ghz. also check out the motherboard I have in my sig its 8x8 and costs around 100 (when i got it). I'm going to add a second 6870 soon and have a pretty similar setup to you..
  8. Hmm yea I wish PCI Express slots were interchangeble like mouse and keyboards...wouldn't that be nice?

    I tested the x4 slot and it is bottlenecking the card anywhere between 15%-25%, which is a very annoying amount. But I have decided to just stick with this mobo for now until AMD releases their next gen of CPUs later this year, that way I can get a new CPU as well.
  9. yeah probably a good idea bc even if your second gpu is being held back you should still have pretty darn good performance in most games
  10. lol I just tested it in Bad Company 2 and I got about 10 frames better when I DISABLED CrossFire...dumb mobo
  11. Best answer selected by thismafiaguy.
  12. nice yeah i mean even a single 5850 should do pretty well in bfbc2 I have a 6870 and a 955 @ 4.0 ghz and my rig just about maxes everything out all high and I get 55-60 fps at 1080p w/vsync
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