Inconsistent MKV scrubbing

[Gaurav25856014nf32]

System: GTX 750Ti 2GB, Ryzen 3700X, 32GB DDR4

Issue: While scrubbing through each frame going to next or previous frame shows way ahead or way before frame respectively for a flash of a second and to the intended frame. That was during each frame scrub but fast playback also has some stuttery playback not smooth while MP4 is smooth.

When: The issue arises when Hardware Encoding is enabled. MP4 scrubbing works fine on both HE and SE method but MKV suffers on HE only. 

Tried on: OBS encoded MKV file with 10Mbps bitrate VBR, 60fps constant, 1s keyframe interval, 1 B Frame. With same settings MP4 files just works buttery smooth.

[Ann Bens]

Your post is not very clear. Which Premiere version and OS

Hardware encoding as in export, or hardware acceleration encoding/decoding in the Preferences?

[Gaurav25856014nf32]

Version 25.5

Windows 11 25H2

Timeline Scrubbing which is obviously HE/SE in the Preferences.

[Ann Bens]

There is no software option for CUDA (anymore)

Hardware acceleration encoding/decoding in the timeline is on or off, nor is there software acceleration.

You cpu card is bare minimum.

[Gaurav25856014nf32]

Software Encoding for Timeline is with Startup 'Only Software Encoding' option. And regarding GTX 750Ti being bare minimum I have been editing on this card for 8 years. And it hasn't broken any sweat for 1080p 60fps low bitrate 10-20Mbps video while it was on MP4 but recently MKV is implemented but doesn't have smooth performance while either 'I remux same MKV video to MP4' or 'I create MP4 file with similar encoding settings' it works just smooth timeline scrubbing and playback.

[R Neil Haugen]

Yes, you've been using that card for eight years, which by computer standards means T-Rex is simply aged, not long gone. There are no driver updates in the future for that card from what I've seen the forum's resident expert on such things say.  And note, most of the 900 series cards are already not usable in Premiere ... that that one is recognized at all amazes me.

There are other options out of OBS, which I use quite frequently, so I would not recommend the MKV encoding if you're working with Premiere. That is your choice, so choose something that works better. Same file data.