First the computer:
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System Information
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Operating System: Windows 10 Pro 64-bit (10.0, Build 19044) (19041.vb_release.191206-1406)
Language: English (Regional Setting: English)
System Manufacturer: ASUS
System Model: System Product Name
BIOS: 2403 (type: UEFI)
Processor: Intel(R) Core(TM) i9-10850K CPU @ 3.60GHz (20 CPUs), ~3.6GHz
Memory: 65536MB RAM
Available OS Memory: 65432MB RAM
Page File: 13690MB used, 61469MB available
User DPI Setting: 144 DPI (150 percent)
System DPI Setting: 192 DPI (200 percent)
GPU nVidia RTX 3090
memory used does not go above 30%,
the videos I edit are no more than 16 GB
CPU use sometimes goes to 25%
GPU use tends to stay below 10%
This is fairly new behavior. I've been using the system for quite a while and it doesn't seem to have a problem with any other software. (I've run benchmarks for both the system and graphics to see if something is going bad wrong ... but they are still were they have been within a percent or two)
If anyone else has had similar and you solved it, please share.