Hello,
This is going to be a lengthy post. I happened to be one of the people who had a micro stuttering problems with my amd 6970s . It was so bad that I was ready to dump my 2 cards cheap on Ebay and fork out for a GTX 590. I was in fact convinced that's what I was doing. The only thing that slowed me down was the fact that all of the major online retailers were sold out of GTX 590s.
Now I would like to note that I am not a fanboy of any brand, not amd, not intel, and not nvidia. I am only a fan of performance, and then after performance my next consideration is value.
Ok so details:
I have 3 asus 24 " LED monitors which run 1920x1080 which gives me an eyefinity resolution of 5760x 1080
When ever I mention that I have a 6970. I actually have unlocked shader versions of HIS 6950s 2 GB version, which run 6970 clocks (and beyond) all day long.
I was originally running one 6970 on a intel q 9300 (stock 2.5)overclocked to 3.48 mhz liquid cooled. This was pushing one card at about 95% CPU load. I was not thinking when I bought the second card about needing extra CPU horsepower. Low and behold I picked up a second 6970 installed the second card and realized that I was completely bottle necked as the cpu was pinned at 100% and my video cards were each pushing about 50%. This was causing major stutters. NOt micro stutters.
I decided that I needed to get a new system. I did some research. Then I did some more research. What I gathered from all of the forums is that in order to truly push 2 high end video cards that I would need to be running an i7 CPU, and that AMD just cant cut it and would bottleneck.
I don't want to get too in depth of why I chose the following system, but I will give some highlights.
I purchased a i7 2600k, a ASROCK Extreme 7 Gen 3 motherboard, and I installed 8 GB of Corsair XMS3 ddr3 which has an xmp profile of 1600 mhz, and is timed at 9-9-9-24.
Highlights of the system are that I chose a beefy CPU, and a motherboard with dual 16x lanes, which in fact are only provided by the third party nvida with the nf200 chip.
I put the system together. and loaded Battlefield 3. Now before I put this system together I was running the game on one card with all high settings, msaa off, AA at 2x, motion blur off, VSYNC ON, and aliasing post = off . ambient occlusion ssaa I was getting FPS ranging from the low 20's - 60 fps and and with vsync off highs of 70s . The game looked well, but I did not appreciate the dips into the low 20's
As soon as I loaded BF3 for the very first time with Crossfire enabled on my new rig I almost barfed. "This looks worse than before " I screamed. The game was supper choppy. After messing with tons of settings I discovered that turning VSYNC off was the only way to get the game to run. Ahh now I was finally getting high frame rates. Frames were staying in the high 50's dipping in the low 40's, and shooting up past the 70's. Then I noticed. "This game really looks like crap, maybe I need a third video card I thought to myself" I looked over my settings and noticed that I was actually running the game now at Medium , and not even HIGH, with ambient occlusion off, mmsa off, aa at 1 x and aliasing post at off ! The game was Micro stuttering to the point where it was simply unplayable and hurt my eyes. IF I turned any of the settings higher it would just get worse.
Ok ok, SO I didn't just give up. I searched for days and days for answers. I tried turning off Hyper threading, I tried the game with every possible settings combination. I overclocked the 2600k to 4.8 GHZ. NONE of this helped. As a matter of fact with hyper threading off I noticed that my 2600k was topping out at times and hitting 100% now and then. It was mainly hovering between 75 and 95 percent. I then proceeded to try new drivers, then old drivers, then old caps. Each time doing an clean uninstall of Catalyst with Driver sweeper. I also used GPU-z to check my used VRAM. It never went far past 1024mb, and these are 2 GB cards. VRam running out is simply not true.
Then for the kicker. I turned Crossfire off, and everything looked smooth again. Yes My frame rates dropped, but if I didn't have Fraps up I would have never known it. Again with one card and crossfire off... Vsync worked fine as well.
Ok so I then decided I have a corrupt OS or a bad driver hanging in my system somewhere. I installed a brand new Samsung spinpoint f3 that I had sitting on the shelf, loaded windows 7 64 bit, installed BF3, and it was simply all the same garbage.
This is when I was convinced that I was selling my video cards. My friend then offered to let me remove his 2 gtx 460's from his AMD RIG so that I could test my cards in his system. I reluctantly agreed to do the test. His system is an ASUS Crosshair V Formula, with a Phenom x 6 1100t (stock clocks), and 16 GB of Corsair Vengence 9-9-9-24 1600mhz ram.
The first test we actually ran was his cards in SLI and NVidia Surround in my system. the resolution his gtx 460s allowed us to run was something like 3000x 1050( not quite as high as what eyefinity allowed, but I suspect its because the 460s are not even close to the flagship card and therefore limited to this lower res. THe cards ran the game on my intel system at ultra on all settings but msaa off, and motion blur off. The vsync was on and working fine. The game looked fantastically smooth . it was dipping into the low 40s but was most certainly hitting 60 fps with vsync on.
Now for the test that we care about. Please note that the only flaw about this test is that our monitors in our test bed limited the resolution to 5040x1050 with eyefinity. ( I will report back with actuall FPS's of 5760x1080 once I recieve my new crosshair and Phenom x 6 this friday. We installed my cards into his AMD system. I was able to turn all the settings on ultra. Every last one of them. The frames were smooth, Vsync worked, and there was no micro stuttering. the game was not holding 60 fps it was dipping into 50s. We then turned down the msaa 2 x, and motion blu off, ambiend occlusion to ssaa and aa to 8x, but left everything else on ultra.
This seemed to be the sweet spot. The game hugged 60 fps for the most part, with occasional dips, and no micro stuttering.
Now. I also noticed that I was getting micro stuttering on my Intel system even when running on one monitor, but it was kinda suttle, but still very annoying to me and once again I preferred playing with one card as opposed to cross firing. I was also having a hard time holding 60 FPS. So We ran BF3 on the amd rig with my 6970s on one monitor. ALl settings jacked to the max. The game was unbelievable smooth with vsync on and held 60 FPS like a champ. With vsync off there was slight tearing and we were averaging around 90 fps with highs around 120.
I would like to make one final statement about the test. His Nvidia SLI cards actually performed better in my Intel system than in his AMD system, yet they did perform Excellently in his AMD system as well.
My conclusion:
Run your AMD cards on an AMD system. They have true dual 16x lanes rather than 8x8 or a fake 16x16 back boned on a nvida chip.
There are a few variables in my diagnosis. For one the problem could just have been my ASROCk motherboard with the nf200 Chipset. I actually doubt this though. I believe the real reason is that the entire chipset is incompatible with crossfire. I also believe that the i7 hyper threading is not optimal for gaming. if you turn off the hyper threading now you are at 4 cores, and bottle necking your cpu. (lets see the cpumark benchmarks with hperthreating off too guys ) can someone post them?
All of the benchmarks that you read online that compare amd cpus to intel cpus use FPS only as the determining factor. Ok so maybe an INtel system can push a few more frames than an AMD system, but NONE of these benchmarks mention the overall look, and fluidity of the game.
According to task manager all 6 cores of his system were at 75% while running BF3. Remember this was a stock clocked system!
If you guys have any questions about my tests please feel free to comment.
Again I will be posting my actual FPS and experience with my new AMD system this upcoming weekend running 5760x1080.
I hope this helps you guys that are banging your head against the wall with your eyefinity crossfire!!!!!
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