Has anyone had issues getting decent rendering speeds out of Intel Quick Sync with Vegas 14? I am able to get 2x realtime rendering out of FFmpeg but when I use Vegas to render I'm doing good to get realtime rendering speeds.
I fixed my problem. The problem only surfaced when I tried to transcode video that was natively 60fps. I am transcoding to 30fps, so the video preview window in Vegas didn't like this transition. You can right-click the video track you are working on in vegas and choose properties. Then, simply change the undersample rate to something that matches your desired output fps.
So, in my case, the original video was recorded at 59.940fps. That means that I need to cut the fps in half for the preview window, so I change the undersample rate to 0.5, which yields 29.970fps playback in the preview window. I'm not 100% certain that saying "this changes the preview window settings" is the correct terminology, but this solved my problem.