100% CPU usage on Dual Xeon

sumitagarwal wrote on 9/12/2004, 5:05 PM
Ok ok... I know Vegas 5.0b isn't multi-threaded and can't really take advantage of multi-procs, BUT... when I run Vegas and I am doing either a real-time video preview (I stack effects on like crazy) or a final render Windows Task Manager shows me as having 100% CPU utilization on all four virtual processors (2x Xeons + hyperthreading = 4 virtual CPU's).
I don't want to sound like I'm complaining (I'm not), but: what the hell is going on?! If Vegas isn't written to take advantage of multiple processors, how is it that all four graphs ramp up to full when I use Vegas?

Thanks.
-sumit

Comments

DouglasClark wrote on 9/13/2004, 12:34 PM
Vegas does use multithreaded/hyperthreaded rendering. I also get near 100% use of both virtual processors in my P4 with hyperthreading.
BJ_M wrote on 9/13/2004, 2:57 PM
1. hyperthreading (with vegas) on a dual xeon system is slower than with hyperthreading off (i have tried it both ways) except in a few cases -- overall i suggest to leave it off.

2. if no filters and you are ONLY encoding to mpeg2 -- vegas will use 100% both cpu's // throw in a filter or two and it will use only one .. but because of system overhead, drive activity, perhaps a virus scanner left on (bad idea), source material decoding (as in some QT types) or the phase of the moon -- you will see 100% or near to it ..... i usually see about 60% ..

but it is more efficient to frame serve from one vegas to another for encoding -- which will harness more cpu power .. or frame serve TO vegas , with the frame server doing all the resizing and cropping and frame serving OUT of vegas to another vegas or another encoder -- I stack up 4, 6, 8 or more of these at once for max. efficiency ...




100% on a hyperthreaded singe cpu is still just 100% on a single cpu in reality ... only a controlled timed test will show a difference (yes it is slightly faster - most of the time)


jsteehl wrote on 9/13/2004, 8:57 PM
"but it is more efficient to frame serve from one vegas to another for encoding -- which will harness more cpu power .. or frame serve TO vegas , with the frame server doing all the resizing and cropping and frame serving OUT of vegas to another vegas or another encoder -- I stack up 4, 6, 8 or more of these at once for max. efficiency ..."

Wow you blew my mind with that one! Can you explain your workflow a little more using this technique... sounds interesting.

BTW, has not been mention yet so I throught I throw it out there, under the Options General Prefs there is a "Disable multi-processor AVI rendering" option. Make sure it is on. Seems to make a diff on a Dual Athlon, can't speak for a Xeon.

-Jason
sumitagarwal wrote on 9/13/2004, 10:32 PM
Yea, that frameserve idea is pretty interesting... I might give that a try. If its so easy for us to implement ourselves with a frameserver work-around, makes you wonder why Sony doesn't build such a technique straight into Vegas. Or, for the matter, it makes me wonder why the mechanics of the network rendering isn't applied to single system/multi CPU setups (I know you can run multiple instances of the render service on one machine, but still...)
-Sumit
BJ_M wrote on 9/14/2004, 7:24 AM
first a note on network rendering and running 2 render engines on a dual cpu -- it works , it works very well ... is it useful all the time ? no ... depends on the project ... biggest problem at this point is that the stitching is so slow as to make the gains realized earlier negated somewhat -- since this is a such a great feature and very useful for for some large projects i work on (and do use it) -- i would expect Sony to work on this area in a future release -- digital fusion has network rendering down to a T as an example --

as for frame serving TO Vegas --- avisynth or virtualdub or virtualdubMOD are the answers --- you do all your preprocessing, noise reduction, cropping , cropping, deinterlacing (if necessary), , adding bugs, frame rate adjustment (BIG thing -- change source frame rate from 24 to 25 lets say and feed it to Vegas - so Vegas sees it as pal), etc etc .... HUGE HUGE savings in time for your final render and working with frame served video in Vegas is just the same speed as working with the original -- it is also a way to feed non program mpeg and other formats into Vegas .... the new virtualdub 1.6 has further refinements for Vegas users as it now allows you to work in different color spaces and other features --


Ive written about this before here -- so a search will turn up some techniques -- but i will frame serve all my source material into Vegas pretty well (i don't use DV material i should point out - but frames, lossless avi , high bit rate mpeg at anywhere from D1 resolution to 4k files) and several other formats ..

i will often use 2 or more Vegas at once - if i am working in 3D , which i do a lot and feed to a third Vegas -- with satish frame serve plug in - it allows you to network frame serve - so i will have more than one machine going --

Last night i had 10 v-dub frame servers going feeding into 2 Vegas - which were feeding into procoder (which queue's renders based on priority) .. when i came in this morning - everything done ..

avisynth and v-dub can also use the same source files and images at once -- which normally in windows is a no no (i don't even know why this works) ..

a BIG BIG thank you must go to Satish for his frame server for Vegas -- which really makes Vegas shine ..