2021 Performance After Uninstalling 2020

I recently took the plunge and upgraded to v.2021. The bruises of past Photo Raw (“PR”) upgrades are still visible (!) so I retained v.2020 and created a test set of photos. Using 2021, I then applied heavy and multiple edits to a range of photos over 10 days. I used small files, large files, JPEG’s, DNG’s, TIFF’s, and Raw files. In Browse, I opened up the whole catalog and quickly scrolled up and down the photos. Finally, I opened large files in Browse, zoomed in, and panned quickly by moving the mouse in a circular motion. Throughout all of these tests, the performance was brilliant – no pop ups, no rendering lags, and a responsive brush.

Here comes the but, and it’s a big one. After the successful testing I decided to commit to 2021 and so I uninstalled 2020. The performance of 2021 immediately fell of the cliff. Opening the same test files in Browse now takes up to 10 seconds, with a progress pop-up window appearing. Zooming does the same, fast panning is now impossible, and brushing is slow to respond. Just to emphasise, these issues only started after the 2020 uninstall, nothing else was changed.

It appears that editing with masks causes the slow down and the threshold is very low. The poor performance starts after applying just three masks to filters or local adjustments on a 6Mb JPEG. The response continues to get worse in proportion to the amount of editing which means that PR is now virtually unusable.

I uninstalled 2021, deleted the ON1 folders in User\Roaming and Program Data, then reinstalled both 2020 and 2021 (b.t.w. the edits were lost in 2020). I repeated the uninstall and deletions for both 2020 and 2021, and then only re-installed 2021. I have done all the usual checks of PR system settings and GPU updates and settings. I also did a Settings Reset during a PR start up. None of these had any effect on the problem.

I raised a ticket with ON1 nearly 4 days ago, but I am still waiting for a response. In the meantime, I thought I would raise this post as a warning to other users who may be in a similar situation. I also write in the hope that somebody may have other ideas on how to fix this!

Thanks.