[Henk Petersen]

I recognize this as errors from the GPU during rendering of effects. In Vegas you can switch off to let the GPU assist (under Preferences). Then re-start Vegas and try again.

[Henk Petersen]

I would not know either.
As an amateur video editer I have once experienced that existing software is not always immediately suited to the newest developments in hardware. My new and expensive Nvidia GTX770 graphics card was a disappointment with video editing and I changed it for a cheaper and older AMD HD6870 card. How this is with CPU’s I really do not know.
I think I would try to make inquiries with the developers of Vegas (now Magix).

Cheers and good-luck

[Henk Petersen]

Hi Peter,

I cannot imagine that W7 instead of W10 would be the cause of the problem.
But yes, I do see the details of the camera files in the Explorer Properties window.

Actually it was not quite accurate what I first wrote to you. My 4K video files “as-is” from the camera are previewed without stuttering. The stuttering starts when effects or transitions are applied. But I usually pre-process my videos in Mercalli 4 stand-alone, which produces 4K output of 280 Mbps. This really stutters in the Vegas preview. When previewing this, the CPU usage rises to 95%. When previewing the 100 Mbps files from the camera, the CPU usage is 50%.
But previewing little-compressed video like .avi files (made by Vegas with the Video for Windows codec) of 3300 Mbps (!) the CPU is used for only 10%. This also stutters, but perhaps that is due to the file being stored on a classic HDD.

So somewhere the CPU performance comes into the picture. Maybe you should try and find user experience from other Ryzen users.

[Henk Petersen]

Having read your communication with interest, I noticed that you speak about new cameras. These cameras produce video with high bit rates. Did you process also these videos on your old computer system without any problem?
My GH7 camera produces 4K video with 100 Mbps. This video in my Vegas 13 Pro the preview in full quality is always stuttery. Using the Build Preview RAM function for very short pieces of video helps out. HD video with 28 Mbps: no problem. The point where stuttering begins is somewhere in-between.

PC W10 64-bit 24gb * Intel® Core™i7-4770k Quad Core 3.50GHz * 8GB XFX Radeon R9 290X
Cameras: Panasonic SD900 and Panasonic GH7

[Henk Petersen]

When I have phenomena like that, it is always due to the GPU being used but not functioning in harmony with the CPU as it should. You can check that quickly by prohibiting the use of the GPU in Options\Preferences\Video. It gets worse as you add effects, transitions etc.