6 hours ago
(This post was last modified: 6 hours ago by Efficient_Good_5784. Edited 2 times in total.)
Overall GPU utilization % isn't 1:1 as much as it seems. It can handle more than one transcoding session using QSV despite a single transcode taking at least 60%. You can test this out yourself by opening up multiple browser tabs and on each playing a different video that's transcoding.
The important part of a transcode is that the transcode fps remains at or higher of the video's fps (to prevent buffering).
You also have to keep in mind that energy used to produce work is measured as a unit over time. So if one method uses more energy at once but finishes the job faster, it's possible for it to use less watt-hours than the slower (and less energy-consuming) method.
You have to measure how much watts your energy usage increases with QSV and see how long it takes for it to complete a transcode. Then the same for VAAPI. You finally compare how much watt-hours each used to see which is more efficient in your system.
The important part of a transcode is that the transcode fps remains at or higher of the video's fps (to prevent buffering).
You also have to keep in mind that energy used to produce work is measured as a unit over time. So if one method uses more energy at once but finishes the job faster, it's possible for it to use less watt-hours than the slower (and less energy-consuming) method.
You have to measure how much watts your energy usage increases with QSV and see how long it takes for it to complete a transcode. Then the same for VAAPI. You finally compare how much watt-hours each used to see which is more efficient in your system.