For reference, here’s a comparison drawing with identical settings, but once with r.VT.MaxUploadsPerFrameInEditor set to the default value of 32:
32_uploads_per_frame.mp4(17.8 MB)
… and once with r.VT.MaxUploadsPerFrameInEditor set to 99999:
99999_uploads_per_frame.mp4(14 MB)
> when you’re testing, say UE5.2.1 vs. UE5.4.3, is the content identical (in other words, did you use a mip bias of -2 in the latter but not the former)? I wonder if the regression could come from such a content issue.
The content was more or less identical. This -2 bias apparently has been there since 2022 and nobody ever noticed.
> But our best theory for what you’re seeing is that between UE5.3 and 5.4, the update behavior was changed, with the introduction of r.VT.RVT.DirtyPagesKeptMappedFrames, which it doesn’t unmap pages (forcing us back to lower res pages briefly) and instead queues the existing pages to be reproduced. You could try setting that to 0, just to see if that leads to the same behavior as UE5.2.1, i.e. that invalidated pages become immediately blurry.
Yes, I think that was it! Setting that back to 0 does indeed bring back the old behavior. I’ve attached a couple of videos for comparison.
But I think we’ll be going with the increased MaxUploadsPerFrameInEditor value anyway, since that is performing fine now and looks a lot better.
Thank you so much for all your help!
Am I that bad at uploading attachments or is this website messing with me?
comparisons.zip(90.5 MB)
> Am I that bad at uploading attachments or is this website messing with me?
“It’s not you, it’s me” - says the website 
You’re not the only one complaining about it (we are too!)
I’m glad we managed to get to the bottom of this. Hopefully you’ll find a good balance for your settings/CVars for both the editor experience and the game. Let us know if you have more questions.
Cheers,
Jonathan