R6950 Crossfire issues

[KingOtaku]

Now, I just began to crossfire my Radeon 6950's. In some games, it works (most notably Metro 2033) but in others it fails completely. In BD2, I lose about 10-20 fps. And worst of all is that in BF3, the game that I specifically got a second card for, crossfire adds absolutely no FPS gain. I just want to know if anyone else has been having crossfire/driver problems in this game.

 

[bystander]

Here's another thing. LCDs don't have a refresh rate. They don't have a electron gun like a CRT do. The hz you see in windows is a emulation because the need to receive the images the same way as a CRT did.
Fps is what your gpu produce. You can get 120fps on a 60hz monitor. Your pc won't slow down or nothing youll just see tearing and ghosting issues because the gpu and the LCD went out of sync. 70 fps on a 60hz is fine. The more it goes out of sync the more ghosting and tearing will appear.
That's why they say buy a gpu to power your monitor not your ego. Then youll be able to eunuch it with Vsync off most of the times. But once you start to overkill youll be using v-sync permanently. Problem with v-sync is that it can drop your fps half your refresh rate which can be countered by enabling tripple buffering to get the fps just below the refresh rate.

To make everything short. V-sync is simply a function to let your gpu know of your monitors limitations.

You are flat wrong or misread what I wrote. While your GPU might generate 120 FPS, the monitor still will only update its images at their refresh (hz) rating. A 60 hz monitor still only updates 60 times per second.

While LCD's do not use a gun, and are solid state, they still only update the screen at the rate of their refresh rate. Why on earth would people buy 120hz LCD's over a 60hz if it didn't matter? Why does 3D on a 60hz monitor perform horribly?

As someone who has both a 60hz and 120hz monitor, I can refute your claim quite easily.

 

[ilysaml]

No, it's always limited to 60 displayed FPS.

You mean that physically it's just 60 FPS displayed and rendered of the "200 FPS" ?

And the eye takes the benefit of much higher than 60 FPS, but your hardware just does not display more than 60 FPS without higher refresh rate.

I just meant this, that if the monitor refreshes at 85 Hz and the GPU is rendering 100 FPS, you don't take a benefit from the "15 FPS", right ?

 

[bystander]

No, it's always limited to 60 displayed FPS.

You mean that physically it's just 60 FPS displayed and rendered of the "200 FPS" ?

And the eye takes the benefit of much higher than 60 FPS, but your hardware just does not display more than 60 FPS without higher refresh rate.

I just meant this, that if the monitor refreshes at 85 Hz and the GPU is rendering 100 FPS, you don't take a benefit from the "15 FPS", right ?

Pretty much Correct. It still renders 100 FPS, but only 85 images are displayed (which may have tearing).

The refresh rate on the monitor is how many times per second it updates it's image.

 

[ilysaml]

So V.Sync can help to prevent "Microstuttering" by enforcing a fixed regular frame update rate no matter how quickly the next frame is or isn't ready the framerate will always be at 60 ???
EDIT: so 2 or more frames of the extra 15 FPS shown on the screen draw when the monitor refreshes at 85 Hz, those 2 or more frames cause the tearing ?

 

[bystander]

When V-sync is not on, the GPU might update the frame buffer when the monitor is half way through displaying what is in the frame buffer. That means that the monitor might only be half way down showing the image in the frame buffer, when another one over writes the original image, resulting in a display image that is half of one image, and half of another (or different fractions).

V-sync does have a drawback when you have lower than than 60 FPS as it can result in sudden drops of FPS in order to stay in sync.

 

[ilysaml]

So V.Synch shouldn't be enabled when i know that i will be getting less than 60 FPS ?

 

[bystander]

So V.Synch shouldn't be enabled when i know that i will be getting less than 60 FPS ?

I wouldn't say that, as you can still get tearing below 60 FPS without V-sync, though it's rarely as bad, but you should be aware that if you see sudden drops in FPS, you might need to turn it off. Depending on the game, and whether it uses triple buffer (or if you can force it on), it may force you down to even multiples of 60, which means 30 FPS or less.

It basically works like this; if it goes below 60 fps, and triple buffering is not used, your video card will not update the frame buffer until the image is completely done and the monitor is in vertical retrace mode (or an LCD equivalent if they call it something else). If the GPU finishes updating before it vertical retrace has started, it will wait and do nothing until it can write to the screen. This means that if your average frame takes slightly longer than 1/60th of a second to create, it'll skip a frame, and do nothing during that time.

However, triple buffering let's the GPU write to 1 of 3 frames that it buffers, so rather than waiting to for vertical retrace mode before it can update the frame buffer, it'll start a new frame and render it in another frame buffer, then it flips the active frame buffer for the monitor to display during vertical retrace mode. This prevents tearing and allows the GPU to keep working, but it can cause a little latency (as you are always seeing an image slightly delayed).

Here is a better written description of what I'm trying to say: http://hardforum.com/showthread.php?t=928593

 

[KingOtaku]

Okay guys, so I installed the CAP 4 Drivers, reinstalled 11.10 preview 3, then moved back to 11.9, reinstalled CAP 4 drivers AGAIN and I am still getting the same FPS and just as much microstuttering(which CAP 4 is supposed to fix)
It just might be my CPU....but in that case, there is no way in hell I can afford a new CPU and the motherboard to go with it....

 

[nicedart180]

This is what I run for my cfx set up for a comparison.

I have an i7 920 @4.0. My crossfire set up: (msi 6950 twin frozr III 2gb) OC 925/1375 no bios changes. I could flash the bios or unlock the shaders for better returns, but, if I am not dipping below 60fps on the highest settings I didnt see the need.

On the BF3 Ultra settings I am running at 70-80 fps at all times. 1920x1080

 

[KingOtaku]

I have 2 6950 Twin Frozr III's also, though they are at stock clocks...
And guys, it isn't my processor. Tom's just benchmarked everything, and I should be getting 2.5 times the fps I've been getting: http://www.tomshardware.com/reviews/battlefield-3-graphics-performance,3063-14.html

 

[cdub1980]

I have 2 6950 Twin Frozr III's also, though they are at stock clocks...
And guys, it isn't my processor. Tom's just benchmarked everything, and I should be getting 2.5 times the fps I've been getting: http://www.tomshardware.com/reviews/battlefield-3-graphics-performance,3063-14.html

I agree with this.

Plus, from what other benchmarks are showing, BF3 is not CPU limited. Different CPU's are showing steady FPS across a wide range of GPU's. The major limiting factor with BF3 in terms of CPU seems to be number of cores as opposed to actual per core performance. The CFX setup you are using should show much better scaling.

On a side note: I do think you need to OC the processor. I have the same processor, it's made for OC'ing and can be done easily.

 

[ilysaml]

I have 2 6950 Twin Frozr III's also, though they are at stock clocks...
And guys, it isn't my processor. Tom's just benchmarked everything, and I should be getting 2.5 times the fps I've been getting: http://www.tomshardware.com/reviews/battlefield-3-graphics-performance,3063-14.html

Did you try disabling CF and run it with a single GPU ? did you get the 39 FPS on ultra ? i just played it today i'm ranging between 41 and 36 FPS on Ultra.
CPU 4.0 or 2.8...no differences at all.

 

[KingOtaku]

Yes, I range between like 35-45, so 39 fps average sounds about right on ultra...One thing I have noticed though, is that switching my settings from Ultra to, say, Low, only gets me maybe a 5-10 fps boost at most, which is not what is supposed to happen.
Also, even though I switched my drivers to 11.9, it still says I have 10.10. Even when I uninstalled all my drivers, I checked on MSI Afterburner and it also said I still had 10.10....It's like the drivers are stuck or something, or CCC and Afterburner aren't working.

 

[bystander]

Yes, I range between like 35-45, so 39 fps average sounds about right on ultra...One thing I have noticed though, is that switching my settings from Ultra to, say, Low, only gets me maybe a 5-10 fps boost at most, which is not what is supposed to happen.
Also, even though I switched my drivers to 11.9, it still says I have 10.10. Even when I uninstalled all my drivers, I checked on MSI Afterburner and it also said I still had 10.10....It's like the drivers are stuck or something, or CCC and Afterburner aren't working.

That's a classic sign of a CPU bottleneck. Everything you've specified sounds like one. Is it possible that your CPU is overheating and getting throttled?

 

[KingOtaku]

No, my CPU never rises above 55C, and from the benchmarks, there shouldn't be a problem...my CPU has worked in all other games, so I don't see why BF3 would be the exception.

 

[ilysaml]

That's a classic sign of a CPU bottleneck. Everything you've specified sounds like one. Is it possible that your CPU is overheating and getting throttled?

Something always driving my to say why people throw the bottlenecking issues on AMD CPUs, all the high end 990X and 890X chipsets are designed for 3-way/4-way CF or SLI, didn't AMD put in mind that FX 8150 or 1090T would bottleneck a CF configurations ?
Another thing to mention, seeing other enthusiasts with HD 6970s in CF and never mention any issues with a bottlenecking, even Toms's community chose a high end AMD based PC equipped with 1090T and 3-way HD 6970

X4 975/980 BE CPUs, those two particularly perform great in gaming compared to i5 2500K in most cases, compared to a X4 965 in the same clock there should be no problem as both are based on per core performance "Deneb" and have the same L3 Cache

EDIT: I've always believed that in most cases, CF/SLI are related to drivers issues and sometimes a hardware configuration when the CPU is strong enough to handle any game.

 

[ilysaml]

@ Kingotaku
I use CCC 11.10 preview 2, it's not official yet but i got to say there's no difference between 11.10 and 11.9 and a third preview released but i guess it's usless for me it's not gonna change anything.

yes i too range between 36-58 FPS but i OCed the GPU to 880 core, 1375 memory with the CPU @ 4.0 GHz.

Try uninstalling the the drivers and patches with driver sweeper clean uninstall, install the latest 11.10 and CAP 4 again, give your CPU the highest OC you can achieve 3-8 or 4.0 and see how it goes.

 

[KingOtaku]

Alright, I'll try doing that, we'll see how things go...
But I looked at the clock speeds of my card while gaming; my first card is at 850/1300 (which is the stock clocks it came with) while the other is idle at 250/150. Is there something I'm missing here? maybe I have the card hooked up incorrectly? As far as I know, you just make sure both cards have power (i.e. the 2 6-pins) and hook them up with a crossfire bridge...

 

[ilysaml]

And you enable CF via CCC and bla bla bla
and some reviews say it's necessary to hook up booth bridges in order not to lose any bandwidth or data connection between the GPUs.

Play a game and see GPUs usage via MSI Afterburner, if both are identical, no GPU is IDLE while gaming.

 

[KingOtaku]

Everytime I attempt to use Driver Sweeper, it crashes. I assume that is not supposed to happen, so any other driver cleaners you'd recommend?
And yeah, I checked; it uses both cards in Metro 2033.

 

[ilysaml]

Wait a minute, do you have this problem only in BF3 ? so other games utilizing CF as it should ?

So just do a complete Uninstall to all CCC features, delete manually any AMD folders that contain previous installations

 

[bystander]

Something always driving my to say why people throw the bottlenecking issues on AMD CPUs, all the high end 990X and 890X chipsets are designed for 3-way/4-way CF or SLI, didn't AMD put in mind that FX 8150 or 1090T would bottleneck a CF configurations ?
Another thing to mention, seeing other enthusiasts with HD 6970s in CF and never mention any issues with a bottlenecking, even Toms's community chose a high end AMD based PC equipped with 1090T and 3-way HD 6970

X4 975/980 BE CPUs, those two particularly perform great in gaming compared to i5 2500K in most cases, compared to a X4 965 in the same clock there should be no problem as both are based on per core performance "Deneb" and have the same L3 Cache

EDIT: I've always believed that in most cases, CF/SLI are related to drivers issues and sometimes a hardware configuration when the CPU is strong enough to handle any game.

While you could be right, the problems he's having does sound more like a bottleneck somewhere. In many games everything runs great, but this one game he sees almost no benefit when dropping down to lower graphics settings. That's a classic case that something is bottlenecking the graphics card and usually it's the CPU.

I have noticed that almost all 6950/70 crossfire complaints come from Phenom and 1090T systems, so I personally don't have a lot of faith with AMD CPU's atm.

Either there is some driver/bios issues, or they don't perform well at high FPS and low resolutions. Those benchmarks often show that the AMD CPU's do bottleneck a lot at lower resolutions, something the OP has. For the crossfire setups to not be bottlenecked by a slower CPU, you need a high resolution that demands a lot of GPU power just to get fairly low FPS.

 

[KingOtaku]

I did a complete uninstall, even got Driver Sweeper to work and used that. Made sure ALL of the AMD files were gone, and reinstalled with 11.10 and CAP4. Doesn't work.
I am completely sure that the problem lies with Crossfire not working, since my second card never activates. I have tried switching places and it's always the same; whichever card is hooked to the Master card remains idle, but only in BF3 (as far as I've tested)
I'm riding this on bad drivers. I have seen a few other people complain, so it's not just me. I will wait another week or so fro AMD to release better drivers-hopefully that will fix it...

 

[ilysaml]

I am completely sure that the problem lies with Crossfire not working.

Are you sure that Both cards are identified by the CCC ? linked to each other ? non of them marked as disabled ?
And you still didn't answer the imp question, did you try other games and saw a benefit from CF ?

 

[KingOtaku]

The only other game I tried was Metro, and a few benchmarks. All of them showed improvement, and they are both enabled and I have crossfire activated in CCC. I'm going to try reinstalling the game and see if that helps at all...I doubt it, but one can hope.