Preview slows down with size filter active

[MusicalBox]

Without knowing your PC specs, the first things I’d suggest is to try Preview Scaling and Proxy Editing

Preview Scaling

The Preview Scaling setting may be used to reduce the resolution of video processing when you are using a fair amount of filters, transitions, and track blending. This may help with the performance during the editing process. [image] However, keep in mind that the source video or images must typically be scaled down to the designed preview scale, and that will have a processing cost. See Proxy Editing for the remedy to that. Proxy generates substitute clips at the same resolution as preview sc…

Proxy Editing

It will have to be checked. Oops, wait a minute… now it’s my bedtime. Maybe on the other side of the Atlantic, you’ll be more awake after this time. Good luck with the tests.

You can also go to Settings and look if it makes a difference if you turn ON and OFF Real Time (frame dropping) and Scrub Audio.