Network Render - 8 Cores to 5 -- Why?

[James White]

First post here, but I’ve been learning from posts here for some time.

You guys have been a big help.

Here’s a mystery I can’t solve.

I’ve got four PCs working together doing Network Rendering in Vegas 8.b

1 – Quadcore
2 - Athlon X2
3 – Opteron dual core
4 – Raid Server

Quadcore, Athlon and Opteron are renderers. Raid Server serves media and accepts finished rendered files.

I am NOT using distributed rendering.

OK, here’s the mystery – When I start a big render job – say 12 veg files – I send out four jobs to each renderer.

All three renderers do the first job at max CPU usage. All three machines are running at 98, 99 or 100%.

In other words, during the first round of jobs, I’ve got eight cores going full blast. Very nice.

However, as each renderer finishes its first job and moves to the second, something odd happens.

Athlon X2 continues to work at 100%. Both cores are pegged.

However, Quadcore and Opteron both scale way back on job 2 and all subsequent jobs..

All four processors on Quadcore are working, but only at around 25% average. Very spiky usage.

Opteron’s two processors keep working, too, but one core works around 90% and the other spikes around a lot, averaging about 25%.

On Round 2 and subsequent rounds, both Opteron and Quadcore have very spiky CPU usage on Task Manager.

The bottom line is I go from eight cores pegged on round 1, to the equivalent of five cores on round 2 and subsequent rounds.

I can’t figure this out. Why should one machine continuously peg the processors, but the other two throttle back?

Everything’s on the same network.

I’d appreciate any insights.

[Jason Robinson]

what output file format is your first render job? I seem to remember somethign about network rendering having different licensing schemes for MPEG2 that specifically disallows the use of multi core / CPU machines for network rendering jobs (ie jobs sent through the network render service as opposed to jobs kicked off via a full vegas instance).

[James White]

Hmm. Hadn't thought of that.

All the output render formats are wmv.

Tomorrow I'll try some different formats to see if that makes a difference.

[Jason Robinson]

Originally Posted by James White

Hmm. Hadn't thought of that.

All the output render formats are wmv.

Tomorrow I'll try some different formats to see if that makes a difference.

I've always had problems with more than 1 render slave machine, so when I need to, I just make sure all the media files are duplicated on my render machine, and then open up a full Vegas instance (same project file as on the edit machine obviously) then kick off a render that way.