Confirmed, Repeatable Frame-Rate Issue in V6

GmElliott wrote on 6/22/2005, 5:46 PM

Finished my last project in Vegas 5 and officially made the switch to Vegas 6 about a 3 weeks ago. During this time I've noticed my preview window's frame-rate fluttering under 29.97fps on footage that has no effects/changes on it. I didn't think too much of it and figured it might be something working in the background on my computer, temporarily slowing it down.

Tonight I'm doing my first multi-cam edit in Vegas 6 and I have 3 video tracks synced up and PIP'd. In Vegas 5 I'd usually set the preview window to "DRAFT-FULL" and still get full 29.87 frame-rate. However, tonight it seemed like it wasn't going over 8fps! After some time toying with it I found that if I switch my view setting to Best-full, Good-auto, or anything other than the setting it was currently at and immediatly switch it back to my normal Draft-Full I would get full 29.97 frame-rate. ...for a few seconds that is. About 5-10 seconds after playing the frame rate slowly and stadily plummets untill it bottoms out around 3 fps.

Again I tested it and switched the quality setting and then right back- and AGAIN it snapped back to 29.97 and slowly plummeted down again.

I decided to test Vegas 5 out- just to make sure it wasn't the drive the footage wasy playing from. I cut and pasted all the tracks into a Vegas 5 timeline...played it back...and it's plays back fine at 29.97fps steady. No problems.

Is this a known issue for Vegas 6? I spoke to Edward Troxel about this and he feels it may be a caching issue. What has changed in Vegas 6 that is causing this? Are there any known fixes for it?
Any input/help will greatly be appreciated.

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Comments

Edin1 wrote on 9/14/2005, 3:10 PM

This may not be a bug!
And something under the hood HAS changed in Vegas 6, but that's its requirements for more memory, besides other things.
Even in Vegas 4, it says that the Dynamic RAM shouldn't be set too high, because some space needs to be left for the Vegas itself, and Vegas tells how much space is approximately available.
There are other things in Windows that require RAM, and Vegas itself may bump up its requirements on the fly, as the project requires.
I understand that having 2GB of RAM, and not being able to use 700MB for Dynamic RAM is a reason for concern and anger, and if nothing else is the issue, then the Sony team shoul (and will) look into it!

rmack350 wrote on 9/14/2005, 6:19 PM

After reading through the thread it just sounds like there's a practical limit to the preview ram setting and that 700 MB is too high. Someone up there on the thread said that he/she was running with a setting around 500MB and things were okay so the gist of it seems to be to experiment a little and figure out how much Ram Preview memory Vegas can handle.

Yes, Vegas also needs memory to run, in addition to what you set aside for RAM preview. And, yes, the OS also needs some memory. But you'd think that if Vegas can run nicely on a 1GB system then if you installed another GB you ought to be able to use it for RAM Preview.

As far as installing more memory, there are still some limits. I don't think Windows will let any application have more than 2GB. And even if you install 4GB you can't address much more than 3GB of it on a 32bit system. The rest of the address space is used for other things besides memory addresses.

Anyhow, it sounds like a little experimentation is called for.

Rob Mack

rmack350 wrote on 9/14/2005, 6:22 PM

Speaking of experimentation, I just tried bumping the previe ram up to 500 from 16 and I see in task manager that my page file usage went way up and my CPU usage went up as well.

Seems like the increased RAM preview setting also increases CPU usage.

Rob Mack

Cheesehole wrote on 9/15/2005, 12:40 AM

Okay this is what's happening. Yes it's effectively a CPU limitation - I'm seeing a frame rate drop instead of a CPU utilization increase because I'm already maxed out on CPU with this composition even before the RAM preview slowdown takes effect.

First, it's not that there is a hard limit to the amount of preview RAM you can use, it's a linear scale.

* Even using 16MB has an effect on preview framerate, it's just not noticeable.

As you increase RAM, the effect becomes more and more noticeable. You are increasing the ceiling that Vegas will eventually hit, and when it hits that ceiling, the framerate holds steady. The higher the ceiling, the more frames will be cached, and the slower the framerate will end up.

Watching Task Manager, I start playback and switch to Draft mode. I notice that Mem Usage and VM size for Vegas drop to about 100MB each and then steadily start to increase. Switching to Best mode makes it drop again, and start to increase.

*So whenever you switch preview modes, Vegas flushes all the frames out of RAM.

Then I watch the preview and the framerate drops steadily as the Mem Usage / VM Size increases, until Vegas hits the ceiling. Then everything levels off.

So as an example:
- I set the preview RAM to 512MB
- then play the project
- it starts off at a nice 16fps
- Mem Usage / VM Size at 100MB
(once I flush the cache by switching preview modes).

After a couple minutes the framerate has leveled off at 5fps, and the Mem Usage / VM Size have stopped at about 620MB.

* So for some unknown reason, having all those frames cached into memory is eating at least 3x the normal CPU power during playback.

The only way I know of to reclaim that CPU power is switching preview modes or doing something else to flush the cache. Otherwise the preview frame rate just stays really slow during your entire editing process.

I tried it with no FX or compositing and it went from 30fps to 8.5fps in a couple minutes.

So maybe Sony could at least tell us if this is a bug, or if it's expected behavior, or if it's a system problem, or something helpful please! :).

Thanks,

BEN

rmack350 wrote on 9/15/2005, 9:45 AM

I'm using a simpler scenario (plain DV footage with levels applied. It's enough to force caching to RAM) so my performance numbers are a little different but here's what I'm seeing:

--After flushing the cache and then starting playback I see my page file usage climb.
----I'm assuming that Windows is paging out other stuff besides my RAM cache.
--My playback is fine until the page file reaches a certain point and then I start to see a lot of disc access. So something is either being paged to disc, being read from disc, or both. In any case, my playback speed drops at this point. I'm going to guess that either Vegas or the RAM Preview space itself is being written to the page file (and so that's the end of ram preview if it's being written to the page file).

In my case I've got 1GB of physical memory. I've set the RAM preview to 700MB. Before playback I have about 790 MB available. Once I've played back enough for performance to hit bottom I have about 70 MB available and a 900MB page file.

For my system I don't think this is too surprising. RAM preview probably IS being written to the page file. If this same thing were happening and I had 2 or 3 GB of ram I'd think it was unreasonable. And evidently it is happening.

So for my simpler scenario maybe Vegas needs to somehow manage the RAM preview space so that it never gets written to page file. Or if it's some other part of Vegas...well, the same thing goes.

If the same settings have the same problems on a 2GB system then maybe the RAM preview needs to use upper memory addresses and then fill down (or something. I'm getting fanciful here.) The idea here is not to compete with other basic and necessary things that are already in memory, like the OS.

Even before your playback performance drops, the CPU usage steadily rises. To me this might suggest that things are being steadily swapped in and out of the page file but I don't have a good meter on my system to look at disk reads and writes.

No real conclusions here. Just observations. Seems like I just can't have the RAM preview set quite so high.

Rob Mack

johnmeyer wrote on 9/15/2005, 10:26 AM

These last couple of posts are very useful to me. For years I have wondered why Vegas seems to sometimes get slow. I figured it was just me. I too had seen the paging file issues, but mostly during renders (especially with still photos which, with Vegas 6, will eventually crash the program).

This information gives me a useful workaround. Thanks to both of you!

BTW, you might want to report this via the tech support link at the top of this page. It is my belief that very little of the information, ideas -- and most importantly -- suggestions in this forum ever reaches the engineering or product marketing staff. Instead, they are set up to receive this through the suggestion and tech support links above.

JJKizak wrote on 9/15/2005, 12:38 PM

I have noticed that the system restore for each drive (monitoring) hugely affects preview performance if it is activated. So After setting the monitoring to only the "C" drive preview performance improved dramatically. The same with all of those cutsey little things checked off like "mouse shadow", etc. After unchecking the whole lot it helped preview performance. Then I jumped on the drive indexing and not too sure about that one.

JJK

bakerja wrote on 12/6/2005, 2:04 PM

I thought I would bump this thread in hopes that someone has new light to shed on a painful subject.

JAB

rmack350 wrote on 12/6/2005, 6:09 PM

What's the painful problem? As near as I can see, too much Preview RAM causes a system to start paging things to disk and then your preview performance drops. Lower your Preview RAM setting.

Rob Mack

GmElliott wrote on 12/8/2005, 7:24 AM

Yes I've been running with a dynamic ram preview of 100megs and haven't had any problems since. The length of my ram renders are considerably shorter but it isn't enough to throw off my workflow.

If/when Sony addresses this apparent issue I'll bump the ram preview back up to a more generous amount.