‘Build Dynamic RAM Preview’ problem in Sony Vegas Pro 10

[John Rofrano]

Try turning Loop Playback mode on (Ctrl+Shift+L). I find that if I make a timeline selection and use dynamic RAM preview with loop mode off it doesn’t always work. With loop mode on it always seems to work.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Stephen Mann]

If I recall, when in loop mode, Dynamic Ram Preview is used by default.

Steve Mann
MannMade Digital Video
http://www.mmdv.com

[Stephen Mann]

Generally, if your timeline is not complex (mostly effects and compositing) then a reasonably fast PC should preview without Ram Preview.

Steve Mann
MannMade Digital Video
http://www.mmdv.com

[Jnnjkn Knknkm]

I generally use a lot of effects and transitions in my videos, so I usually have to use Build Dynamic RAM Preview.

[Jnnjkn Knknkm]

It’s still not working…

Thank you anyway, though.

[Matt Crowley]

As far as I can tell (and this is in Movie Studio 10) the dynamic RAM preview system caches all frames that get rendered to the preview window/device. So, playing a short selection of your project in loop mode will go a bit sluggish at first, but the dynamic RAM preview cache will accumulate rendered frames and after a couple of loops, the selection will play smoothly. Each pass will add as many frames to the cache as can be rendered in real time, and the rendered frames from the previous passes will be used to speed up playback. This happens in normal (non-loop) playback too.

If you do a “build dynamic RAM preview” then loop the selection, it should immediately play smoothly because you’ve forced Vegas to do a non-realtime render of ALL selected frames.

Any normal preview playback while editing adds to the dynamic preview cache but, as soon as you make an edit, the corresponding cache contents become obsolete and get binned, forcing re-render of that part of the timeline when you preview.

If you set the cache size to zero, all previewing will be done in real-time, or as fast as the CPU allows. Complex sections may be stuttery/sluggish because the renderer can’t keep up. If you set the cache to a modest value (say 256MB) you’ll only be able to create a small dynamic RAM preview (at 256MB at 1/4 size preview, I got a max of 20secs). If you set the cache size too big, Vegas sucks up RAM that would otherwise be used for media and other apps.

I noticed that if I try to create too large a RAM preview, the selection gets shortened and the preview doesn’t always play properly – as if the preview cache gets lost/corrupted and I’m back with not-so-realtime preview. Maybe that’s what Chloe was seeing. Forcing Vegas to build a new dynamic RAM preview (with the adjusted selection) usually sorts it out.

[Mark Davidson]

I’m having issues as well. Ram Preview never works right in Pro 11 (build 701)64bit on my Win7 64-bit machine.

I use cineform AVI files since otherwise I’d be mixing MOVs with m2T files from two different cams.

As soon as I add NeatVideo and adjust the color levels, I can no longer edit due to the lagginess. I’m using preview (full).

When I do a ram preview, it just plays a few seconds. Dynamic Ram is at 200 MB.

And to think I was going to let my spouse handle the editing part of the business. It looks like even in the year 2013, it’s almost as if one needs to be an IT Pro to edit in HD.

AMD Phenom II X4 955 3.2 GHz
ATI Radeon HD4670
8 GB Memory

[Paul Griffin]

I know this is an old thread but I have had the same problem with Sony Vegas Pro15 and hope this can be useful. For me the problem was solved by changing the Project Properties – Pixel Format from 32 bit to 8 bit.