So I've recently upgraded to quite a big new build: - Intel i7 5960X @4.622Ghz. - 32GB DDR4 RAM (XMP set at 3Ghz). - Asrock X99 Extreme 11 Motherboard (there are two 4 pin molex pins that are being supplied power from PSU - required for 4 graphics cards). Motherboard is also on the latest 1.20 bios version. - 2 x 295X2's in Crossfire (1st card in 1st slot, 2nd card in 4th slot - as per the manual - both running at 16X PCIE 3.0 rate). - EVGA G2 1600W (both cards are connected to the GPU power ports with 2 x 8 pin PCIE). Also tested with a spare extra PSU to distribute the load. - LG 34UC97-S 34" x 2 monitors (both displays connected to the card in 1st slot via miniDP to DP cables). My issue: https://www.youtube.com/watch?v=cXnz7dDBVkc&feature=youtu.be Basically it's like one of the GPU's is a frame behind (maybe more than one frame) resulting in this kind of frame skipping/stuttering issue. When I disable CrossfireX games play perfectly, and frame rate is high. The annoying thing is that I'm still setting world records (I'm number 12 in the world in 3dmark Firestrike Extreme): http://www.3dmark.com/fs/5399018 I've read reviews of Quadfire and no reviewers mention these kinds of issues, but I'm inclined to believe they've been told to skip over these issues by AMD (Ferrari syndrome - won't be supplied any future cards). I'm just looking for a resolution to this issue, as frame rates seem high but the stuttering makes games completely unplayable. Any comments appreciated. I've also raised a beta report to AMD's driver team: http://www.amdsurveys.com/se.ashx?s=5A1E27D279D83B32 but not sure if they'll respond or even look into it (after all there don't appear to be thaaaat many Quadfire setups).
It sounds like stuttering which is down to using four GPUs. Unfortunately, there's nothing you can do without driver updates from AMD to resolve such issues.
When you go past a certain number of GPUs the drivers that are out are just not designed to cope with the number of gpus you have. (applies to Nvidia and AMD) Benchmark software like 3dmark are designed to use every GPU avail. In the real world there is no game that can use more than 3 gpus. And the 3rd gpu is usauly not doing alot in those cases. Adding a 4th gpu has always come at a cost of stuttering or min fps drops. ( More noticeable on AMD side the stuttering, Nvidia side is Min fps drops but it does have a more stable frame pacing which results in a better experience.) People on this forum have tested both Quad SLI and Quad CFX and have noticed these issues before. Review testing for Quad SLI or Quad CFX is done by very few review sites none of whom id state are trust worthy. Bit-tech to this day do not even suggest SLI or CFX setups in place of single gpu solutions. 295x is still the fastest single card solution avail when cfx works fine. Send the other back? or send them both back and buy a couple of fury x or 980 ti. You wont set world records in 3dmark but you will get a better game experience. Which I assume is the point. If its world record attempts then disable cfx for gaming and have fun. Will also vary widely by which games your testing. Newer games like GTA 5 have alot better CFX and SLI driver profiles than say Just Cause 2 would have.
Tbh I have never experienced any of the reported problems and I've had quad SLI as in my sig for years I get the feeling it's more to do about the kind of games you play. You could try turning off "core parking" not saying it's the answer though http://forums.bit-tech.net/showthread.php?t=187645&highlight=Core+Parking
I was afraid of the answers posted in this thread. I think the best solution currently is to remove the second 295X2 and wait for the next round of GPU's as a single one is good enough for my resolution (most of the time!). I'll give that core parking a try though... Interesting.
Okay PM sent, and I've disabled core parking. No discernable difference (although I was running 'High Performance' power saving mode).
Multi-GPU configurations are often problematic. PCPer reviews are a good way to see this because they measure individual frame times, which show that AMD cards have a particularly hard time with GTA V (and nVidia cards don't exactly like it either). These sorts of problems usually end up being fixed by new drivers... eventually... maybe.
Good find, now that's how you benchmark a game! Hmm, shame as the frame rates are great. I wonder how they'll be able to fix this?? Maybe DX12 will help things on a bit as it'll alleviate the CPU from draw calls?
Its not a cpu issue, on your setup the chances of it been cpu related are as close to 0% as you can get them. DX 12 will not be a instant fix games still need to be coded for it, Its not a magic bullet most review sites have urged this caution. Once its implemented all SLI and CFX games designed on it will use SFR for there rendering instead of AFR. You could use SFR where its available certain games have this option available. That would remove the microstutter. I know for Civ beyond earth theres a driver profile specifically for the title. SFR does have 1 disadvantage that people like to bring up and thats it will kill your average fps if such a thing matters. pcper is very good for gpu reviews as they show everything that will actually effect the end user and its just a graph that has this performance on it.
I ran quad R9 290s without any frame pacing problems at all. I got killer framerates with crossfire enabled. The only problem was they had massive issues with running 4k across displayport without constant picture dropouts.
