Enable Multicore preview playback?!?! - who knew?

FrigidNDEditing wrote on 4/11/2009, 7:53 PM

I would like to know how many of you out there knew about this and didn't tell me.

ok, while reading another thread I came upon the statement that you can enable multicore preview playback.

While I do not condone doing this I found some interesting results while doing it.

To enable multicore support you have to access the internal preferences tab, which cannot be done unless you hold down shift when clicking on preferences, then clicking on the "internal" tab, and doing a search for playback will allow you to find it "enable multi-core rendering for playback"

I tried playing back some chromakey footage with it off (default) and on my q6600 I got about 10-11 fps in best full with some SD footage I had laying around, and I had a chromablur on there too.

I also tried making a 7 video plane composite all in 3D space, and then moving that all in a parent 3D track (also in SD) at between 10 and 15 fps.

Then I enabled multicore....

for the first chromakeying, I even resized and set to best full with chroma blur and keying on, and got full 23.976

same for the second, even though I had all that 3D motion, I still had 23.976.

For 3D motion, in 1080HD 24P, I actually get a drop in performance with this enabled ( all gen media ) making it between 3-4 FPS, but with it disabled I get between 4-6FPS after changing the parent 3D motion to make sure it's not using any pre-rendered RAM buffered footage.

For keying and motion blur on some HDV footage I have had laying around, and the multi-core rendering for playback enabled, I got .8-.9 fps. and with it disabled (default), I got 1.1-1.2 fps.

All these tests were done with Best Full scaling on, and simulate and scaling video to fit preview window on from the right click menu on the preview window.

All projects were matched to footage to enable the best performance.

Would be curious to see what others may get, but remember that you do this at your own risk, and while I'm not sure that anything bad may happen, I do not condone mucking about in the internal prefs of Vegas... they're hidden for a reason.

Dave

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Comments

blink3times wrote on 4/17/2009, 5:12 AM

"Still avaiting for a cure for the 4-core render issue when rendering AVCDH to HD... but that's another (sad) story...

Try this:
http://www.sonycreativesoftware.com/forums/ShowMessage.asp?MessageID=647907&Replies=54

blink3times wrote on 4/17/2009, 5:21 AM

"Dave,

Actually I brought it up:
http://www.sonycreativesoftware.com/forums/ShowMessage.asp?ForumID=4&MessageID=647764

And I have been using this switch since version 7. There have been no adverse effects at all. There are some issues it helps on... and some not. What I have noticed is that it seems to help in the first 30 seconds or so of playback., then it reverts back to skip and jump. Maybe a bottleneck some where else.

farss wrote on 4/17/2009, 5:30 AM

"Difficult to say whether this is only a question of a given FX's good optimization (or lack thereof), or simply the amount of CPU work it requires. I'm tending to think it's the former, basing on the CPU load indication..."

I'd say "d) None of the above."

Levels FX, pretty simple, each pixel is processed independantly.
Unsharpen Mask requires entire frame analysis to first find edges the use something some form of convolution to enhance them. Each pixel and it's neighbours need to be processed and the results go back through a loop. Difficult to impossible to split the task over threads.

Let's not ignore the workload of audio processing either. Some audio FXs can be very CPU intensive. The top shelf audio FXs are still run on DSPs.

Bob.

megabit wrote on 4/17/2009, 5:59 AM

I'd say "d) None of the above."

...and I'd say "Both" :)

Christian de Godzinsky wrote on 4/17/2009, 6:13 AM

Blink3,

OK - the credit goes to you for mentioning it here first. But some credit goes also to Dave that started this independent subject/thread. Othervice I (and many others) just would not have noticed it embedded in another thread.

Credits also to you Blink3 for finding an workaround for the memory issue with AVCDH projects. Do you also claim that with this modification (of making some of the vegas dll's and exe's aware of more than 2Gbyte of memory) ALSO solves the 4 core render problem?

In other words, can I render with these modifications also AVCDH material out to HD formats - using all 4 cores - without issues?

Christian

blink3times wrote on 4/17/2009, 6:22 AM

Credit is not really the issue... just setting the record straight..

According to others... they're now rendering with all 4 cores. I am anyway and i couldn't do it before (with avchd)

All you can do is give it a try. Evrything to gain if it works... and nothing lost if it doesn't.

johnmeyer wrote on 4/17/2009, 8:06 AM

I stopped by to help out Andy with his marvelous, professional deshaker script that replaces my horrendous hack, and in doing a quick scan of the forums, found this thread, along with the one on using a utility to modify DLL memory usage.

Good stuff.

I tried using this tip on 8.0c under Win XP Pro. What I found is that multicore playback definitely makes a big difference on playback of external media (I was using HDV native m2t files).

However, it actually seems to decrease playback rate of internally generated media. I have several hundred VEG files people have posted over the years, and I randomly tried a few dozen of these (things like 3D titles), and every one played slower with multi-threaded render enabled.

So for most editing that I do, I will enable this feature (unless I find it affects stability), but when I create titles and the like, I will turn it off.

As for knowing about this, it has been mentioned in this forum occasionally, going back at least a year. See this from exactly a year ago, from DJPadre:

Serious render flaw V7 and V8

Also, it is mentioned from time to time on other forums. Here's a description, also from a year ago, in one of the Canon forums:

Sony Vegas 8 on Vista 64

This is very enticing stuff, but my recommendation to everyone is to save your work every five minutes, and change the VEG file name very half hour, just to make sure that you are sufficiently backed up.

plasmavideo wrote on 4/17/2009, 8:52 AM

Howdy John! Great to see you posting! Can't wait to try this trick tonight.

Tom

CorTed wrote on 4/17/2009, 9:14 AM

Welcome back John. We missed you !

Ted

jabloomf1230 wrote on 4/17/2009, 10:42 AM

Hey John,

You must have noticed my post in the HV20.com thread, were I said that I couldn't see any impact of the multicore setting. I've never found this setting to do much, either good or bad. But I am going to go back and look at it again, from the standpoint of the observations (internal vs. external) that you made in your post.

I suspect that the impact is related to whether various filters and codecs can take advantage of multiple cores in an efficient manner.

rtbond wrote on 4/17/2009, 3:22 PM

I just tried the "enable multicore ..." setting on v8.0 and 8.1 running under Vista-64 (6 GB RAM) and saw NO improvement in HDV playback performance.

I have a Core i7 (i.e., quad core) machine that can never do much better than 10 fps when previewing to an external 1080p DVI monitor (i.e., secondary monitor) at Best/Full. Interesting to note, however, that the Vegas preview window runs at full rate rate, even when undocked and maximized on the secondary monitor (just once I push the Preview to External Monitor button on the docked preview window the frame rate drops). CPU never gets much above 20% (even when multicore preview was enabled)

wm_b wrote on 4/21/2009, 1:37 AM

I finally got a chance to try this setting. Nothing happened in particular. I also used the memory setting mentioned in the other thread. Still no improvement. I am generally transcoding my AVCHD with neoscene and I can get smooth 24p playback with no effects. Add curves or color correct and I am back down to 16 fps or so.

The other night I was going through some old SD files and I was BLOWN away with how easy it was. Fast, responsive and SMOOOOTTTHHH. It's been many months since I've done any SD and it was dramatic difference. Hopefully the new x58 compy I'm building will bring back some of that enjoyment.

Seth wrote on 4/21/2009, 11:28 PM

Blown away... by how much damage I just did to my system. Have to reinstall Vegas now :(