Render dropping performance midway through after source change

SnarfConsortium wrote on 10/1/2023, 11:24 AM

I recently changed my recordings to a lower resolution to try and get a smoother editing experience with Vegas Pro 20. Went from a 4k60 recording in OBS to a 1440p60. I got a much better editing performance like I wanted, but when I choose my normal render options, just the Magix preset for h.264 1080p60 via NVENC, my performance is halved. My system was typically able to render the projects out at 100+fps (typically around 110-140). But now when I render my projects with the same preset my performance starts off initially around 120fps, but my CPU gets taxed to 100% and performance is tanked down to around 50fps.

Am I misunderstanding the render options? I thought Nvenc meant it would be primarily using my GPU (a RTX 2080ti) and hardware encoders instead of my CPU, and this is what I saw in my previous projects that were in 4k. But now with the lower resolution, when I look at my performance center my GPU is only around 20-30% and my CPU is maxing out at 100%

Comments

RogerS wrote on 10/1/2023, 12:03 PM

You can try one of the two benchmarks in my signature to eliminate the media as a variable. Are your times with NVENC in line with similar systems?

Over % aren't very helpful for understanding what the GPU is doing. Click on the 2080 in task manager/performance and look at encode, decode, 3D, etc. If it's sitting there waiting on the CPU to send it frames it may look like it's not doing much (the spaces between pulses of encoding will grow wider).