@Musicvid - I’ll give it a go. Any tweaks to that Template?

For FAST, I use the 720p template regardless of source.

Here's a barebones 720p 18Mbps CBR template I made that suits me nicely for quick, portable proofs.

My own tests with QSV h264 were deplorable quality.

@Musicvid - Thank you, from the bottom of my wallet! Finished for the day, but this’ll be the first thing on the morrow.

@Musicvid - Made the Template, but it didn't reduce the PreRenders time taken for render. I need to reflect on just how efficiently VP Previews Nested Timelines. Hmmm... 😔

It's really very close to being the same as Vegas' native prerender format, except I came at it from the same place as you -- starting with HW codecs and working my way down.

I did finally get the O'Jays tv special looking good with QSV h264, by setting it at CQ 14. That made it larger than with x264.

So yes, our parallel investigations seem to have left us "culdesacked" once again.

@Musicvid - Well, I tried. But, at the end of the day, shouldn’t VP be able to Preview with all my extra muscle in this MONSTA!

Fortunately for you, it's the codecs holding back your CPU, not the other way around.

@Grazie Have you tried a pre-render with one of the NVENC templates? That may be the fastest option.

Regardless, I do think your experience points out the need for a Vegas intelligent caching system that works in the background to pre-render slow sections of the timeline. This is how other NLE's achieve the appearance of smooth playback. Vegas is able to play back simple events at full frame rate, but always seems to hiccup on transitions, titles, and other composited elements (nested timelines included?) A background caching system would pre-render just those parts.

@Grazie Have you tried a pre-render with one of the NVENC templates? That may be the fastest option.

@Kinvermark - Yup, see my opening statement. First thing I tried.

Regardless, I do think your experience points out the need for a Vegas intelligent caching system that works in the background to pre-render slow sections of the timeline.

@Kinvermark - Well, these are Nested Timelines in a Parent Project. This raises the possibility/question that these Children Nests aren’t actually a proxy? Is this true? If so this is a big trick/opportunity lost. Any thoughts?

I can see SFAP0 files for the nested timelines, but I think these are only audio proxies. I am not sure there is a video proxy being generated... maybe someone else knows for sure?

I am not sure there is a video proxy being generated... maybe someone else knows for sure?

@Kinvermark - There has to be some kind of single file to make it Play frame-rates etc etc. What is this “thing”?

I may be mistaken, but I believe there is an SFVP0 file that is created for nested projects.

Have you tried preview and pre-rendering without nesting? Do you have the same performance issues?

I have looked in all the likely places... can't see any.

Have you tried preview and pre-rendering without nesting? Do you have the same performance issues?

@wwaag - I’ll give it a go tomorrow. However, it’s a complex Parent (lol 😆) and whole point was to experiment with the NEW Nesting. Oh, I found a Bug and had it confirmed by MAGIX. Another thought..... I’m wondering what would happen if I made a Parent, which has Track a Motion, of the Parent? Would that make things slicker?

It makes no difference between Preview or Good / Best preview quality.
It is possible that sfvp0 is just an audio proxy. That would also explain the sluggish and sometimes faulty playback, such as a lost video stabilization. To speed up the rendering, I render the subproject into a new track and hide the others.

Much more bothers me, especially on longer projects, the unload / load procedure. Although only one subproject is changed, all must be unloaded and reloaded.

Yes, it is an audio proxy.

Yes, it is an audio proxy.

@Marco. - Understood. So, what’s the thing that’s Video sitting on the Timeline?

For the sake of simplicity, let's say a project is just a set of pointers to a "bunch" of media files in some configuration. That's what is sitting as "video" on the master timeline.

.......let's say a project is just a set of pointers to a "bunch" of media files in some configuration.

@Kinvermark - Yeah, I guess so . . . dang.

I am not using a nested timeline -- but I think that must make a difference -- prerenders seem perky here.

I gave up on nested projects years ago (albeit with earlier versions) since the render time was increased substantially. I found it much easier to render out individual projects and then combine them afterward using readily-available 3rd party tools. Hopefully, that has changed with later versions, but perhaps not.

I gave up on nested projects years ago (albeit with earlier versions) since the render time was increased substantially.

Ooh, that sounds like a worthy test. Then lots of speculative cause-and-effect discussion. Isn't that what we like around here?

Stay tuned.