Dynamic RAM Preview & Rendered File Size: voodoo?

vtxrocketeer wrote on 5/25/2012, 6:02 PM

Just before a render, I habitually decrease RAM preview to about 56 MB, no matter what kind of render I'm to perform. Today, a render from 1920x1080 Cineform avi to 1920x1080 Cineform avi kept stopping at 2GB with the message that the rendered file size exceeds the file limit. Huh?

I tinkered with all kinds of settings and then, on a whim, increased RAM preview to 1024 MB. Now I render with no problem. I guess on previous longform projects I forgot to implement my habit of decreasing to 56 MB.

I have no idea why this happened; I'm happy that everything is working. Still, can anyone explain this Vegas voodoo? What has RAM preview got to do with rendered file size?

-Steve

Comments

VidMus wrote on 5/25/2012, 8:19 PM

I use the Vegas default. What happens if you use the default?

O.T. Good Heavens! I am so used to doing a CTRL+S that I just did it in an attempt to post this message. LOL!

ushere wrote on 5/25/2012, 9:15 PM

vm - what did you save it as? ;-)

VidMus wrote on 5/26/2012, 7:33 AM

I saved it as, "12-12-2012-Vegas-Pro-12"

vtxrocketeer wrote on 5/26/2012, 9:11 AM

Having fun? ;)

I have no idea what the default RAM preview size is. Vegas simply loads whatever value I had in last.

Anyway, I had no problems with a setting of 1024 MB during my render. I don't like stumbling upon solutions, preferring instead to figure out WHY something worked.

rmack350 wrote on 5/27/2012, 2:18 AM

Seems like a "Feature-like bug". It should make no difference.

Rob

mudsmith wrote on 5/27/2012, 12:45 PM

Being a pretty new user, and not having adjusted the video preview RAM, I am assuming the 220 or so size I find in the menu is the default.

Any reason you would, by rote, be reducing this figure before a render? Trying to free up more memory for the render?

What are folks in general doing with this number, and why?

.....when I bump mine up, Vegas tells me to be careful, I might be stealing too much ram from other processes.

What is best practice here?

amendegw wrote on 5/27/2012, 1:16 PM

This my have no relation to this "voodoo", but supports the counterintuitive aspects of setting Dynamic RAM: http://www.sonycreativesoftware.com/forums/ShowMessage.asp?ForumID=4&MessageID=785178Render Time Strangeness[/link]

...Jerry

vtxrocketeer wrote on 5/27/2012, 4:39 PM

Thanks, Jerry. That was a useful read. I just don't have the desire to figure out why the RAM preview value in my case (or the cases in your thread) have the effect it does. Too low a value, however, seems the thing to avoid.

As I mentioned above, I set mine at a healthy 1024MB (8GB total system RAM), and monitored the render in the Task Monitor. Memory never was an issue. Hrmph. I'm not complaining.

Now back to the regularly scheduled holiday weekend (for us Yanks)...

Steve Mann wrote on 5/27/2012, 6:25 PM

There's no mystery - it's in the manual.

Video Preview RAM is used simply for caching a selection of the timeline for real-time preview. (Select a region then press Shift B). If you never use the Shift-B Ram Preview option, then you can use the minimum amount of Preview RAM that Vegas requires. I suspect that there are some legacy functions in the Vegas Software that uses the Preview RAM as a scratch space because there is a specified minimum size of Preview RAM.

From the help files:
"The maximum size of the RAM cache is displayed to the right of the control. You must leave at least 64 megabytes available for Vegas Pro (more if you are creating complex projects). If you reserve excessive amounts of RAM for your RAM cache, performance may decrease."

All RAM assigned to the Preview RAM is unavailable for any other process, so if you set 50% of your RAM to the Preview Cache to get some long Shift-B previews, you essentially starve Vegas processes of RAM and risk getting data swapped in and out of your Windows Paging Files on hard disk.

amendegw wrote on 5/27/2012, 6:53 PM

"There's no mystery - it's in the manual... If you reserve excessive amounts of RAM for your RAM cache, performance may decrease"If you read the thread I linked above, render performance actually increases (improves) as Preview RAM is increased - up to a certain point. That's still a mystery and counterintuitive to me.

...Jerry