2 x 7950 Crossfire Performance

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undrt0w
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2 x 7950 Crossfire Performance

Post by undrt0w »

Hey its time to use your help awesome techies.

So, last week I bought a second GPU as I've told you and I was really disappointed to see my fps jumping around like maniacs. Now, I am starting to think that it might be my fault but it just doesn't make sense. Here is the setup:

1 x PCIE 3.0 x16 = new 7950
1 x PCIE 2.0 (PCIE 3.0 x4) = old 7950

The only difference is the clock of the new one. It's 925 Mhz, while the older has 810 Mhz. The driver is the latest stable (not beta).

I play with these settings: http://forum.symthic.com/battlefield-4- ... highlight=

Now, when I play Locker the average FPS i get from Raptr is 120 (I cap them at 144 since this is my monitors refresh rate) When I play other maps though, I would go as low as 50 fps. I noticed at Goldmut yday that at a certain point on the map my fps would just go down. Then when I move to another point they will go up. I don't think this is normal since I have seen ppl keep constantly 120 (I will try capping them at 120 and lowering the in-game resolution to 120Mhz).

These are the two cards:
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When I play, the secondary GPU will get more % usage than the primary. If the first is around 40% the second would be around 80%. Can't remember the specific number but in overall GPU 2 would have a larger percentage of usage. Is this because the first runs at the same speed as the second (because of the PCIE) and hence is not so overloaded?

Today, I tried recording with Dxtory and FPS were gone! Just watch this short clip below:
phpBB [video]


Also, when I get good fps, occasionally my game would be distorted for a millisecond...like its blurring for a split of a second. I am pretty sure it's not a game visual. So, any ideas why this might be happening? I think doing a crossfire is pretty straightforward. Just plug-in the video cards, connect them with the bridge, see if in CCC crossfire is enable and that's it. Am I missing something? Could this be me? I guess I need to check other games as well, but still no time to do that. I played PS2 on Sunday...at some point we were a pretty big group at a tech plant and fps again dropped to 30...hence my worries the problem lies with me.
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Re: 2 x 7950 Crossfire Performance

Post by Necromancer »

whats your overall specs? CPU, RAM, OS.
did you notice how much RAM and CPU is being used when your FPS drops down?

It seems to me that SLI/Crossfire isn't very optimized. A lot of people with 2 card configuration complaining about low FPS or instabilities in various games.
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Re: 2 x 7950 Crossfire Performance

Post by undrt0w »

yeah, i just wished i had read about it before spending the money :)

i5 3750K
16GB RAM
Windows 7 x64

I have set BF4 x64 to run by default by Origin.
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Re: 2 x 7950 Crossfire Performance

Post by A Docile Sloth »

Have you tried it in the x32 version of BF4? I've found the 32 to be far more stable than the 64. May help but may not.
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Re: 2 x 7950 Crossfire Performance

Post by expandas »

Your Crossfire performance, driver and game optimizations aside, will be dependent on the lowest common denominator.

Have you tried setting both cards to the same clock and memory speeds? What about moving your higher-clocked 7950 to the PCIe 3.0 x4 slot to compensate for the older card's lower core clock?
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Re: 2 x 7950 Crossfire Performance

Post by undrt0w »

expandas wrote:What about moving your higher-clocked 7950 to the PCIe 3.0 x4 slot to compensate for the older card's lower core clock?
That was how I initially had them...but I thought, why put a better card on a slower port.

I will lower the clock to 810Mhz. If everything ok, I will start increasing it by increments of 10 till I loose stability.
If that doesn't help, I will switch them.
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Re: 2 x 7950 Crossfire Performance

Post by sushi »

interesting I get a blurring effect also once in a while, could it be a "game feature" in the 64bit version, if sloth is right, anybody else having that effect?
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Re: 2 x 7950 Crossfire Performance

Post by Phyrefli »

Used to have a 2x5870 setup. When recording with Dxtory it effectively drops you out of xfire so you're using just one card.

One of the reasons I ended up back with a single GPU setup.
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Re: 2 x 7950 Crossfire Performance

Post by undrt0w »

ha, that's just nice...so now no recording as well :)

yeah, i'd love to get more feedback on that blurring thing.

btw, i've been reading that several things could help solve the prob:
1) setting power control settings to boost cards in CCC to 20%
2) running both cards at the same clock rate

will test tonight and see

this raptr program...does it do anything when optimizing your game ??
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Re: 2 x 7950 Crossfire Performance

Post by A Docile Sloth »

There is a blurring when, I think, the ECM drone goes over. It kinda makes a spectrum on the edges of objects. Or at least it's a problem everyone seems to be having. I think I've had it with both 64 and 32 (definitely 32). If that isn't the blurring then it may be something else.
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Re: 2 x 7950 Crossfire Performance

Post by Jokerle »

They will remove/fix the blurring.

First some mod(?) said in the BL forum that it was from the commander EMP and intended, but later the consensus was that it is indeed a bug. E.g. It appears also without commander.
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Re: 2 x 7950 Crossfire Performance

Post by kidbagz »

Jokerle wrote:They will remove/fix the blurring.

First some mod(?) said in the BL forum that it was from the commander EMP and intended, but later the consensus was that it is indeed a bug. E.g. It appears also without commander.
Yeah.. cuz an EMP should not blurr a humans vision.. but then again... since our ingame soldiers eyes act like a camera (lensflare and no exposure comp) maybe the soldiers are part robot and EMP does affect them slightly??? Maybe they all have robot eyes and htat how they get to see the HUD and doritos in the field!! Maybe we are all robots!! Maybe this is all a dream... Maybe... i'll just see myself out now..
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Re: 2 x 7950 Crossfire Performance

Post by Necromancer »

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Re: 2 x 7950 Crossfire Performance

Post by undrt0w »

So, after the weekend tests the results are:

Bring down faster card to 810Mhz: Still dips and crappy fps
Move to 820 then 830: Still same sh*t
Clock the slower and have both at 925Mhz: Better results with average of 80 fps. Slower card has one fan so temp goes up to 80 degrees.
Remove slower card/No Crossfire: 100 average fps.

Also, how can I have max fps on Locker but then crappy fps on the other maps....does the game know that's one of my fav maps?

I also installed the latest beta drivers from AMD. No apparent difference. I feel crap now...just spent 600 dollars on what??
I AM PISSED!!! :evil: :evil: :evil:
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Re: 2 x 7950 Crossfire Performance

Post by TheYonderGod »

What's your motherboard, do you have them in the right slots?

On the Z77 chipset they should both be running at PCI-E 3.0 8x

If you're using a 4x slot, even though 3.0 4x technically should have enough bandwidth, it might be running off a secondary chipset instead of the CPUs PCI-E controller, which will cause problems.



Download GPU-Z and check what they're running at
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Depending on your config, they might be running at a lower speed while idle; click the question mark to the right and start a render test to make sure they are under load (or check while a game is open)
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