Hi, I've been having very long export times tied to low CPU Usage while rendering videos and I'm unsure as to why. I tried exporting a 2.5 hour podcast and the export took upwards of 7 hours. In a similar vein, creating a low res proxy of a 1 hour file took 3.5+ hours.
My system is an Acer Nitro 5 laptop, i7 9750h CPU and RTX 2060 GPU. CPU Usage while rendering has been floating between 15-26% and GPU usage floats from 13-25% usage for the most part. I feel like something is wrong with this and that especially my CPU usage should be higher (GPU usage I'm not concerned about here). This laptop is <2 months old (got it for Christmas in December), and my old ASUS laptop with a weaker/older CPU was able to render the podcast (older episodes of around the same length) in the 2-3 hour timeframe I expected for this laptop and never had issues with low CPU usage while rendering.
The timeline for the podcast has a bunch of still images/text files and the podcast video was recorded in mp4 with VFR (I realized after some research this doesn't help - but it hasn't caused issues for the months prior). I'm exporting with h.264 at 1080p60fps, Software Encoding (tried Hardware Encoding earlier today but didnt seem to make a difference?), VBR 1 pass Target 10mbps Max 12mbps, AAC 320kbps, 48kHz, Stereo.
My only potential lead is that the CPU is potentially overheating? Using NitroSense, the CPU temp has peaked at 96 degrees C while rendering this project, floating between 85-96 degrees for the most part. Although I have read that those temperatures are normal for this laptop, so I don't know if it has much weight.
I've been digging through forums for a while trying to find a solution and the only solution I've found is to convert to the file using handbrake. While it works, I want to see if there is an alternative solution that doesn't require file conversion, or just the knowledge that this is a hardware/software bottleneck.
While converting with handbrake my overall CPU usage goes up to 90-100%, and rendering with the handbrake file takes export times down to the ~2 hours I expected for the podcast with 70%+ CPU usage on average.
If there's any more information that could be useful let me know - I'm not really an expert when it comes to codecs and the sort. I just screen record videos and put them together for Youtube for the most part and am confused as to why my cpu usage has suddenly capped around 25% while exporting.
I seemingly remember watching that video from anotehr forum post before making this post and not getting anything out of it, but watching it and testing it again this morning I seem to have fixed my issue. Disabling hardware accelerated decoding entirely is letting my CPU render a 50 second clip from the podcast in ~1 min, whereas with Nvidia or Intel enabled it would take ~5 mins. Thanks!