Optimizing renders - 32bit vs 64bit

TeetimeNC wrote on 5/24/2012, 5:38 AM
I have a client who is rendering a large number of 320x240 wmvs at 500kbps. They are running Vegas 9.0e 32bit on a Windows7 64bit OS. I suggested they increase their ram from 8GB to 16GB and go with Vegas 10 64bit, which would be able to take advantage of the additional ram.

However...

I ran some tests on my PC and got some very surprising results. When rendering a 5 minute segment of their footage the 9.0e 32 bit rendered in about 1:42. When I did the same test in 9.0e 64 bit and 10.0e 64 bit, the render time INCREASED to about 9:30. The 32 and 64 bit renders appeared to start at about the same rate, but 30% through, the 64 bit renders really slowed to a crawl.

Why would this be?

Also, am I correct in thinking that although Vegas 32 bit can only access 3GB, multiple instances of Vegas 32 bit on a 64 bit OS can EACH use up to 3GB, so it would still be advantageous to increase the ram if we are editing and rendering in multiple instances. I think this is correct because on my 64 bit os, when I open 10 or so Vegas 9.0e 32 bit instances and start a few renders, Task Manager shows the memory usage increase to 9 GB.

Conclusion

I seems that if I want to optimize these particular renders I should stay with the 32 bit version of Vegas. Can anyone dispute this (surprising) finding?

/jerry

Comments

TeetimeNC wrote on 5/24/2012, 9:43 AM
Ok, it appears there is something screwy going on with my video pc. I just reran the test on my i7 laptop and got these results:

Vegas 9.0e 32 bit: 3:14
Vegas 10.0e 64 bit: 3:49

/jerry
rmack350 wrote on 5/24/2012, 11:31 AM
As shipped, 32-bit Vegas can use up to 2GB of RAM. If your renders are completing, and faster than they would in a 64-bit Vegas, by all means use the 32-bit version.

The advantage to using the 64-bit OS is that there's a lot more RAM available across the board for Vegas and Windows and anything else that's running. And that would benefit multiple instances of 32-bit Vegas since each could get access to physical RAM more easily.

Rob
TeetimeNC wrote on 5/25/2012, 12:27 PM
I really need to step back from this a bit and get some new perspective. I am hoping someone here can suggest something I am not considering, because it seems there must be a better way.

We receive dozens of videos a week that are shot with hidden cams. A typical video will be 1.2 hours, 720x480 MPEG-4 in ASF wrapper, 4000 kbps.

In Vegas, we put a title in front of it and possibly cut small portions of the footage, perhaps to 1.1 hours, and then render to 320x240 WMV, 500 kbps.

The time to render is roughly 1:1 (one hour video takes one hour to render). As you may have guessed given the 500 kbps bit rate, quality isn't as important as small file size and faster renders.

Here are a couple of things I have played with:

1. Just to get a point of reference I tried transcoding to 320x240 500 kbps mp4 in Handbrake but it was not much faster.

2. I thought maybe if we did an unattended batch transcode to an intermediate like 320x240 500 kbps mxf, we might be able to then use that in our Vegas project and improve render speed, but it was also slow.

Any of you have any thoughts on a way to speed up these renders? I have Vegas Pro 8, 9, 10 and 11. I am ok with using something other than Vegas if it would render these significantly faster. And obviously, faster hardware would help but my tests are on a fairly fast I7 940 with 16GB ram.

Thanks,

/jerry
TeetimeNC wrote on 5/29/2012, 8:18 AM
I'm bumping this because I know most of the Americans on this forum have been (like me) off on holiday ;-). Do any of you have any thoughts on the best way to optimize rendering of 720x480 MPEG-4 ASF, 4000kbps to 320x240 WMV (or MP4), 500 kbps?

Thanks,

/jerry
rs170a wrote on 5/29/2012, 8:28 AM
Jerry, have you tried using Windows Movie Maker to see if it renders any faster?

Mike
TeetimeNC wrote on 5/29/2012, 10:04 AM
Mike, I just downloaded the trial Sorenson Squeeze. It transcodes my 720x480 4000 kbps ASF to 288p 512 kbps MP4 in about 40% of the runtime (i.e., 100 seconds of footage can be rendered in 40 seconds), and it can batch render. Now, if I could bring that mp4 into Vegas, add a title, and render out to 288p without Vegas having to re-encode the MP4 I would be golden. This is so because we could batch transcode unattended on a separate computer, then do the Vegas edit/render during normal working hours. I'm off to see if there is a way to stitch a title and the transcoded mp4 into a new mp4 without having to re-render.

Anyone know if there is a way to avoid re-encoding the MP4 in Vegas? To reiterate, I am looking for the fastest way to produce a 288p 512 kbps MP4 or WMV that has our original footage AND a custom title slide.

Thanks,

/jerry
TeetimeNC wrote on 5/29/2012, 11:25 AM
Mike, per your suggestion I tried Windows Movie Maker and it does render much faster than Vegas - 6 minutes to render a 32 minute clip. Vegas takes about 22 minutes minutes to render to the same size/bit rate. Is this due to the difference in the VFW that Vegas uses vs DirectShow that WMM uses?

Based on the above, I'm thinking a possible work flow is to render to the above format using WMM, then batch process using Sorenson Squeeze to get the 288p 512kbps MP4's we desire. The only possible issue I see is sometimes we have to normalize the audio in Vegas before rendering. I can't do that in WMM.

Now I'm wondering if there is something between WMM and Vegas that could render fast AND give me more control over the quality parameters and audio than WMM?

/jerry
TeetimeNC wrote on 6/3/2012, 2:51 PM
I've revised my requirements and resolved some performance issues I was having on my video PC. I've performed some more definitive tests to help me determine how to best streamline our workflow. Basically, we need to take a high volume of footage from minature hidden cameras, do basic edits to remove unwanted segments and add a title, and publish the resulting video to the web.

Tests
I tested three approaches. The test source footage was 24:47 of 720x480 XVID in an AVI wrapper, 30 fps. All renders were to 720x480 768 kbps, 30 fps.

1. Windows Live Movie Maker rendered the source to WMV in 5:15.
Advantages: fastest render time, and free

Disadvantages: Can't run multiple instances, no batch capabilities and output is limited to WMV

2. Edius Neo rendered the source to WMV in 16:17
Advantages: None

Disadvantages: Slow

3. Vegas 10e 64 bit rendered the source to WMV in 16:23, or MP4 in 11:33
Advantages: Can edit and render multiple instances concurrently, can render to various formats, and can batch render.

Disadvantages: Some AVI files have to be transcoded in AVIDemux before Vegas will see the audio, and there is a greater learning curve for the client relative to WLMM.

Conclusions
If I can find a way to eliminate the AVIDemux transcoding step for Vegas for those files that use the 0050 audio codec, it would be the clear winner for me. Even with that limitation I think the ability to do overnight batch renders still gives Vegas the edge.

Questions
1. Why is there such a dramatic difference in render time for WMV between Vegas and WLMM? Both resulting render files are the same size, same bit rate and on this crappy footage I can't say either has a quality advantage.

2. Why is Vegas still on VFW? This causes annoying codec problems that neither Edius nor WLMM had to deal with. I spent hours searching for a 0050 VFW audio codec that would let Vegas see the audio in my source footage to no avail. Bummer.

/jerry