I am trying to share my experience from last few weeks, because I am so frustraded right now. For 10 years, I am using VEGAS for production and editing. In general, I have no problems with software - I also understand that some "things" cannot ever be fixed. But my frustration is persistent for more than month now because brand new problem.
Just to be clear, I am using Pro 15 Build 216 on brand new computer: Intel Core i9-SkylakeX, 32 GB DDR4, 1 TB NVMe M.2 SSD, NVIDIA GTX 1080Ti, Windows 10 64bit Professional. Basically, I am using latest drivers available for motherboard, chipset, GPU, etc.
The Vegas is working fine for few minutes after boot of mentioned system. But unfortunately, after some minutes of editing, when I import a lot of videos (it doesnt matter what type of format it is: H264, MOV, JPEG's etc), performance is hitting hard bottom. I mean waiting for 2 seconds after making "cut", when trying to open the cropper edit or any other sub-application window. And that's for classic 1080p footage, imagine 4K NVENC videos captured using NVIDIA shadowplay - that's horrible to even get videos on timeline - I have editing slideshow on timeline :).
In Task Manager, I can see that Vegas is using on first core (Core 0) the 100% of available compute power once I get at least 2 videos on timeline. When I kill Vegas.exe, this 100% usage drops to normal percentage (10-15% on average). But that's seems strange. It looks like VEGAS is trying to process something on background? But I am not aware of any new function which can cause that... I didn't also find any settings in Options which could help with that.
I think the horrible playback on timeline (i have GPU acceleration active) is caused also because of some bug in decoding NVENC videos, MOV's or H264 in current version of Vegas.
Aren't here anyone with similar problems like I have?