Has anyone else noticed, with the latest beta update, that generating video preview thumbnails is much, much faster?
After moving to a new, and more capable Windows 10 server, I started generating video preview thumbnails for all of my movies, by analyzing about 30 movies per day. Since I’ve been doing this process every day for a few weeks now, I’ve become accustomed to how long it should take to generate thumbnails for that many movies, and the average CPU load during that time.
Since updating to the new server version, Plex is tearing through movies at 4 or 5 times the speed as before. In addition, the process would require 70%-80% CPU utilization before the update, but now it hovers right around 30% CPU utilization.
I know there were a lot of transcoder fixes in this last update, but this was unexpected and most welcomed! Thanks Plex team, this is great!!
Do you have a GPU, and if so, is Plex using your GPU to generate thumbnails? Or is it just reduced CPU usage alone? I’ve asked about GPU thumbnail functionality previously, but I never got a response from plex.
I can’t test this despite running the latest version bc I am in the middle of a now 26 hour Music library scan…
Yes I have a GPU (Nvidia Quadro P2000), and hardware acceleration enabled. In the past, I’m pretty sure the GPU was not used for thumbnail creation. If it is used now, the impact is minimal, like 1%-2%.
No the new stuff does not utilize the GPU. Theoretically the GPU could be used, but due to potential technical issues such as not being able to fall back properly, it’s not used for generating these indexes.
GPU for thumbnails worked great with that previous transcoder hack/script, which hardcoded always on NVDEC.
not HW thumbs is going to become a bigger problem in the future as HEVC content becomes the default codec, and leaving the cpu to process hevc for thumbs is as problematic as trying to use cpu for hevc for real time transcoding.
queue thousands of future threads about why is plex burning up my cpus for thumbnails.
well, I hope that hw thumbs effort is kept in progress (even if not a super high priority), otherwise as per my previous post, it seems extremely shortsighted to leave HW unused when it could be used.
even if HW thumbs were only used for hevc content, that would be a fair stopgap solution.
The new method is only using keyframes to generate the thumbnails, which don’t rely on other frames to be decoded to transform them to JPEGs (keyframes are self contained, only intra-coding used), by this method HEVC and AVC keyframes aren’t drastically different as far as compute time goes for decoding. The heavy CPU usage from the old method was primarily in the video decoding, not the JPEG encoding.
Based on my testing of generating the JPEGs with an Intel GPU (vaapi decode and mjpeg_vaapi encode), the new keyframe method is faster than using the GPU.
And a massive thanks he deserves. This is incredible.
Having moved away from running Plex locally, my online server pointing to Gdrive is far less capable. However this has stripped 50% off the time it takes to generate a VP thumb with a 12GB AVC file.
But even generating a VP thumb for a 4K remux I’m maxing out at 17% CPU usage whilst it does it.
This is the biggest thing in Plex since…
…well since all the Music awesomeness in the same release.
