8 Core Optimization For Vegas

jrazz wrote on 5/3/2008, 5:20 PM
Any tips on having Vegas utilize every ounce of processing power that I can squeeze out of 8 cores?

What I find now is that it rev's up during render and then backs down and then rev's up and then backs down. It does this over and over again until the render is complete. What is more, on John Cline's render test it takes several seconds longer to encode with 8 cores enabled as opposed to 4 cores. Any suggestions?

j razz


blink3times wrote on 5/3/2008, 5:28 PM
In you other post regarding this, i suggested that you go into "internal settings" (hold the shift key down while clicking on Preferences and the extra tab marked INTERNAL will come up) and towards the bottom you will see "maximum number of cores". Change this from 4 to 8, close vegas and then restart.

Others have stated that this has worked for them (I don't know.... I only have 4 cores)
jrazz wrote on 5/3/2008, 7:23 PM
Yeah, that is what I did and that was how I was able to do a render test with 8 threads active and with 4 threads active. And, what was odd is that the 4 thread setting allowed for a faster render than the 8 thread.

So, anybody using 8 cores in Vegas? If so, what are you doing to maximize their usability in Vegas?

Thanks for the tip on the thread count Blink.

j razz
rmack350 wrote on 5/3/2008, 7:45 PM
I'm not sure if I'd view that as odd or just take it at face value. Maybe what you're seeing is that dividing up your particular task amongst 8 cores incurs more overhead than it would with 4.

Rob Mack
jrazz wrote on 5/3/2008, 7:51 PM
So, maybe it is just the render test? I will render some other files to see what it does, but could it be that 32 bit Vegas has reached its limit with 4 core processing?

j razz
rmack350 wrote on 5/3/2008, 8:34 PM
"...but could it be that 32 bit Vegas has reached its limit with 4 core processing?"

I couldn't say, but there are always a number of factors like how the particular codecs you need to use perform when their work is divided 2, 4, 8 ways.

If a juggler has 8 balls in the air does she juggle faster or slower? How fast can she move those hands? Maybe the balls need to stay in the air a little longer.

jrazz wrote on 5/3/2008, 10:01 PM
So, I tested some other files and really can't tell much of a difference. Sometimes 8 threads shaves off a couple of seconds and sometimes 4 threads does. There really isn't much difference in using either setting. Maybe I am missing something?

In my testing I found that if I use a normal project file (normal for me) the cores don't rev up and then go back down over and over again. They all hover around 50-67% when utilizing 8 cores. They also do the same when utilizing 4.

j razz
Musician wrote on 5/3/2008, 10:38 PM
jrazz, how much RAM do you have on your system? I read somewhere that it is good practice to have 2GB per core. If you are running a system that is low on RAM, it is possible that there is not enough memory to go around to keep the processors working at maximum capacity. Just a thought.
Coursedesign wrote on 5/4/2008, 12:27 AM
Insufficient RAM per core for sure.

After Effects has the same "problem."

With Vegas you won't need 2GB per core though.

jrazz wrote on 5/4/2008, 5:30 AM
I have 8 gigs of DDR2.

j razz
Coursedesign wrote on 5/4/2008, 9:14 AM
Could you render whatever you are rendering in 1 core in 1GB?

If you're rendering say HDV, 8 GB may not be enough for 8 cores.

Kennymusicman wrote on 5/4/2008, 10:00 AM
At this point, it's probably worth reminding that not all codecs are multi-core - so depending on what you're rendering to will have a large impact on core utilisation
jrazz wrote on 5/4/2008, 12:37 PM
I am rendering out to mpg-2 (M2T) primarily (and for the render test from John Cline).

Can I change the amount of RAM used for encoding in the internal settings? If not, I could do two cores and two gigs of RAM. I don't have any 1 gig sticks.

j razz
UKAndrewC wrote on 5/4/2008, 3:57 PM
What is your disc setup? Maybe that's the bottleneck?

jabloomf1230 wrote on 5/4/2008, 7:35 PM
As you probably already know, if you hold the Shift key down when you click Preferences in Vegas, you will see the Internal Tab. There's been a lot of fiddling with these debug settings by people on this message board, but most of the supposedly "improved" settings don't do much positive in IMO. As has been stated, you can increase the maximum threads to 8 and you can increase the amount of RAM used by Vegas from the default value of 384 MB.

But whether either of these settings will benefit an 8 core setup is questionable. First of all, without some of tinkering, even under Vista x64, Vegas won't use more than 2 GB RAM total, which includes whatever you have reserved for RAM preview (I use 0 MB, except if I need to use RAM Preview). If you search this message board, you will find the threads about the "Large Address Aware" tweak. I've also found that modifying the Vegas exe header does nothing for performance, but maybe that's just me. In 32 bit Windows, you might as well not even bother with this approach.

It does appear that Vegas itself is the bottleneck with rendering on an 8 core machine. But as a previous poster wrote, I wouldn't rule out your disk system as a possibility for the bottleneck.
jrazz wrote on 5/4/2008, 7:50 PM
I have my RAM preview set to 16 megs (which I have had since version 6 I believe).

As for the disc setup, I have 2 sata 10,000rpm drives in a non-raid environment. One only has windows and Sony Software on it (it is SATA 0) and the other is for renders. I am going to add another 10,000rpm drive for the captured media so I will have Windows/programs on 1, captured media on 2 and rendered media on 3.

Currently I have tried external firewire 7,200rpm drives as well as eSata 7,200rpm drives in addition to the setup above (and a mixture of both) and the cpu's perform the same.

It is looking as if the limitation is Vegas 32 bit and not so much my system. I could be wrong, but that is the direction I am leaning. If that is truly the case, there is no benefit of having 8 cores if you are only going to run 32 bit Vegas. Hopefully I am wrong, but that is where things are pointing.

j razz
Coursedesign wrote on 5/4/2008, 8:52 PM
Instead of getting another 10,000rpm drive for media, get a WD 640GB 7200rm drive for $109.99 w/free 3-day shipping instead.

It's both faster and less expensive.

How can a 7200rm drive be faster than a 10,000rpm?

Higher bit density, so each revolution transfers more data.

I also have a bunch of WD 10,000rpm Raptors in my work station, but won't buy any more until they catch up performance-wise.
jrazz wrote on 5/5/2008, 7:02 AM
Thanks for the heads up on the drive (I am going to order a couple today). It still does not explain the poor utilization of 8 cores.

Anybody else out there have 8 cores and running a 32 bit version of Vegas? What is your experience?

j razz
Coursedesign wrote on 5/5/2008, 10:16 AM
After Effects CS3 supported 8 cores under OS X right away, but not under Windows XP or Vista initially, I'm not sure if they support it even now (I don't have an 8-core system).

So this seems to need some code support in practice.

My understanding is that each core has to run a separate instance of the whole program (needed modules).
jrazz wrote on 5/5/2008, 10:56 AM
I ran across this and think it supports the conclusion I have drawn: 32 bit Vegas does not utilize 8 cores nearly as efficiently as 4 cores.

On the two-core 8710p, Vegas used nearly 100% of both of its processors during rendering. On the four-core xw4600, the number averaged around 97%; on the eight-core xw8400, the number dropped to 44%. Adobe numbers were similar, though less well-defined. Neither program used eight cores nearly as efficiently as four, producing similar or even slower results on the theoretically faster system.

You can read more here.

j razz
rmack350 wrote on 5/5/2008, 11:26 AM
It sounds like you're thinking that 64-bit Vegas is somehow going to do better.

Rob Mack
Coursedesign wrote on 5/5/2008, 11:42 AM
Jan Ozer's reasoning in that article made my head swim, as I'm sure it made his.


The current Intel quad CPUs are really 2 separate dual-core CPUs in one package, this leads to inefficiencies in multi-processing.

Memory bandwidth also becomes a major issue when you're trying to thread together a processing load over 8 cores. This may be solved over the next year.

And disk subsystem performance will of course matter greatly if you're using a less processing-intensive codec.

I don't think anyone should go nuts on spending to get the last few percent of performance from the "ultimate 8-core today," because there will be much improvement with upcoming CPU & mobo architectures, both on the PC and Mac side.

Today, it seems AE CS3 is doing significantly better on the Mac Pro than on PC workstations. One real-life test I saw recently rendered the same heavy-duty clip in 6 minutes on his PC workstation and 84 seconds on his supposedly comparable Mac Pro. One component of the difference is likely to be the Mac Pro's 1600 MHz FSB. Also its memory bus has top performance, but I'm not up to speed on comparing it with top PC work stations.

(I don't recall disk details, etc., so I can only say that AE CS3 seems to run faster on the other platform right now, not how much faster.)

Added: "The Harpertown [in Mac Pro] has a larger L2 cache -- 6 MB versus 4 MB. Plus the North Bridge now has a 24 MB snoop filter which maintains an index of all cached data in each processor. This significantly reduces data traffic on the FSB, providing lower latencies and greater available bandwidth to handle requests between CPUs."

jrazz wrote on 5/6/2008, 6:39 AM
This is interesting. I hooked up an external that had a previous project on it and I opened up the veg file and went to encode last night as a test. I had it downconvert to SD using the DVDA widescreen template. Before I went to bed, it was chugging away at an average of 85% for all cores (8) and it would sometimes swing up to 99% while it would also swing down to the upper 70's as well.

Well, something happened as when I got up this morning Vegas was no where to be found and my mpg file was just a place holder as it was 0 bytes. I am currently letting it encode to M2T and it is hovering around 80% for all 8 cores but it will dip into the 60's and during one portion where I am using Rays by Velvet Matter, it will crank up to 100%, but it does so cyclically. It will quickly drop off to around 60% and then jump back up to 100%.

Anyways, I just thought I would share what I found out thus far.

j razz
Seth wrote on 5/6/2008, 4:10 PM
Vegas Pro 8.1 will have complete support for 8 cores. I saw the demo with my own eyes at the SCS booth at NAB. It's pretty killer. Vista 64 required.
busterkeaton wrote on 5/6/2008, 7:18 PM
your system.

So you need to be careful when you change them. There is a reason they are kept hidden.

This warning should be posted any time internal settings are mentioned on this board.