Noticed quite a large drop in performance with 18.8.2 on Doom in Ultra settings on my RX 560. Usually I play at 1080p with 80% res scaling (so rendering basically around 900p) and am able to run at 60fps 98% of the time with just a few drops. While I haven't played Doom in a while so this may have occurred with an earlier optional update, when I booted it back up recently with the same settings as usual I was getting drastically lower performance in Ultra settings - ~40fps in some scenes, particularly with transparent windows. At high it's closer to before. Did a clean re-install of the 8.2 drivers, no difference. So downgraded to 18.5.1 - bam, performance in Ultra mode back to what I expected at 60fps.
As well, this isn't particular to 18.8.2, but has always seemed to be an issue - resolution scaling in Doom only works with specific numbers, such as 80%. Trying to set a scale above/below that results in either large black sections, or coloured lights around the interface. If this works it would be ideal as I could probably do 1080p at 90% on high and get the same performance, but it's not an option - 80% is the first drop where the graphics don't go wonky, so I put up with the blurriness and at least can choose Ultra settings.
Then again perhaps resolution scaling wouldn't even be necessary if Adaptive V-sync worked as well...
Think the performance regression just might have been a driver quirk, installed the 18.9.1 but did a clean install this time and doesn't seem to be a regression after all.
The res scaling graphical artifacts however still remain. This is what it looks like for most res scaling outside of 80%:
Ultra settings on a 560 ?
Maybe have a read of https://www.tweaktown.com/guides/7757/doom-graphics-performance-tweak-guide/index.html
Yes, at 1600x900, which it can run Ultra just fine at (better than high at 1080p at least). The initial problem however was not that I expected more out of the card in Ultra mode than it should be expected to deliver, the issue was that (at the time) there was a marked difference in performance between driver revisions.
Regardless, the problems remaining now are the resolution scaler producing artifacts except for specific values, and the lack of adaptive vsync in Vulcan - a tweaktown article about the games graphic options (and one written before the Vulkan patch was introduced) has nothing to do with those.