Widescreen Gaming Forum

13.8 Beta 2 drivers are out here. I was really hoping for Frame Pacing to come to Eyefinity resolutions with this release, but the release notes don't say anything new about Frame Pacing. From the looks of it, this one's mostly about improving performance and bug fixes in specific games.

AMD is releasing this technology in phases. The driver today, Catalyst 13.8 Beta is Phase 1. In Phase 1 Frame Pacing only works at resolutions up to 2560x1600 on a single display. That's right, Frame Pacing will not work on CrossFire in Eyefinity resolutions in Phase 1. In Phase 1 only games that are DX10 and DX11 are supported, no DX9 games will work with Frame Pacing in Phase 1.

Phase 2 of the driver will come later this month. In Phase 2 CrossFire in Eyefinity resolutions will be supported. There will also be support for DX9 and OGL games in Phase 2. So if you game in Eyefinity, or across multiple displays, or higher resolutions than 2560x1600 then Phase 2 driver is what you will have to wait for. Also, if you want support in DX9 games.

I do want to note before anyone comments ask this question: no enabling Vsync in the game or the control panel does NOT fix or change these problems.

As a result, everything we are seeing in our 5760x1080 testing today does carry over to 4K monitors and gaming.

The stepped tearing issue is caused by a different but related property – AMD does not appear to have a synchronization step on each scan line but instead on each pixel. Rather than wait for each scan line to output before updating the frame buffer AMD allows the buffer to update at any point which would cause the variable height frame results we are showing you above.

I asked AMD for more information on why or how this is happening but they decided not to comment at this time. When I approached NVIDIA they said only that they have enabled “locks and syncs” for their frame copies and scan line outputs on SLI.

UPDATE: We did finally get some feedback from AMD on the subject after quite a bit of back and forth. Essentially, AMD claims the problems we are seeing are due only to synchronization issues and NOT from bandwidth limitations. Since the file copies are done over the PCIe bus, only an instance of near 100% utilization on it would cause degradation – and the only instances of that would be from heavy system memory access. However, if you are accessing main system memory with the GPUs in your PC then other performance bottlenecks are going to creep up before CrossFire scaling.

If that is the case then AMD should be able to fix the CrossFire + Eyefinity issues in the coming weeks or months. A bandwidth issue would be much harder to deal with and could mean a fix would have never arrived for HD 7000-series users.

While attending AMD’s 2014 GPU product showcase, we were able to pull aside AMD’s PR reps and get a comment on the matter.

AMD is currently targeting a mid-fall release for the phase 2 fixes, phase 2 being the frame pacing improvements for Crossfire Eyefinity. Based on what we’re hearing that would be a November release, however AMD has also made it clear that they’re trying to push these fixes through as fast as they reasonably can.