An update on the state of drivers:
- AMD's latest Catalyst Beta (Catalyst 14.2 V1.3) fixes the translucency artifacts in HDR mode. This driver also supports the newest cards and has correct brightness levels in HDR mode, so if you're an AMD user on Windows, this is the driver to use. This change hasn't made it to the Linux AMD proprietary driver, but it probably will soon.
- I have received reports of faint red lines on the latest NVidia Windows WHQL drivers (334.89) under cloudy conditions, but neither Chris nor I have been able to reproduce them. If you can reproduce this, please file an X-Plane bug. (I have not reported this to NVidia because I can't reproduce it.)
- Some users have reported crashes with Intel HD 4000 GPUs on Windows; getting the latest drivers from Intel seems to fix the issue. I don't have good info on what versions work/don't work but it appears that plenty of machines have shipped with old drivers for their motherboard graphics. I believe X-Plane does run correctly with the Intel HD4000 series GPUs on Windows as long as the right driver is installed.
- OS X 10.9.2 is out, and I think it may have new drivers (the NVidia .kext files changed versions), but I don't see any change in framerate for either NV or AMD cards.
Update: NVidia has been able to reproduce the red lines bug - we're still working out the details of what's going on, but it's a known issue now. Thanks to everyone who reported it.
If you find a driver bug on Windows or Linux, please repot this to us (via our bug reporter) and to NVidia, Intel or AMD. I try to bring known bugs directly to the driver teams, but having the bug in their public bug reports is good too - it makes it clear that real users are seeing real problems with a shipping product.