I do a lot of video editing and usually when I'm rendering a video, the CPU usage hovers around the 90%-95% mark but the last few videos I've rendered have only been using 45%-50% of my CPU and because of this, the rendering time has increased. If I intend to do something else on my computer during the rendering, I will usually limit Vegas to just half the cores (manually bringing CPU usage to 50% overall) so I have enough to do what I want, like gaming. Afterwards, I reset the affinity so it can continue rendering at a faster rate. I noticed it wasn't using as much CPU when the render time of a video was roughly double what I expected. It was a video I had rendered previously. I was rendering with the exact same options as before. The only difference was that I had cut off a few seconds from the end I forgot the first time. I checked the affinity and it is set to use all cores. Looking at the performance tab in Task Manager, it's inconsistent on how much of each core it is using. I have checked my resource monitor in to see if something else was bottlenecking it but I couldn't see anything doing so. I'm at a loss on what to check next to try get Sony Vegas to use more CPU again. Does anyone have any suggestions as to what may be causing the low CPU usage? My Spec: 32GB RAM 8 Core 3.61Ghz Processor 3TB 7200 RPM Sata III HDD <-- This is where the video is being rendered to 120GB SATA III SSD <-- This is where Sony Vegas is installed.