PDA

View Full Version : How to best take advantage of Dual processor G5



Cinewalt
05-27-2005, 08:07 PM
I've got a dual 2.0 G5 with 2.5Gb RAM. Is there any reason not to always stick with 8 threads multithreading for renders? I've heard people talk about using screamernet to utilize the 2nd processor - but isn't it already being utilized by the normal render operation? Are there other optimization parameters that speed up renders using this setup? I've seen similar posts, but no one seemed to have specific recommendations. I'm new to Lightwave, BTW, and I'm loving it!

drclare
05-28-2005, 05:27 AM
It depends on the scene and what you are rendering. Some plugins are not multithreaded and don't use the second processor at all. Many people have found that when rendering hypervoxels it is actually much slower to use more than one thread. It is not an excact science and requires some testing to see what works best. Using screamernet does use both prossecors to their full potential, but you cannot split a single frame into two renders without needing to do some post-processing after. For animations it is a good idea though. I use a dual 800MHz G4 and have found that on average 4 threads seems to be the fastest.

Captain Obvious
05-28-2005, 12:15 PM
Just set it to eight and you'll be fine. If you think it takes too darned long to render, experiment with ScreamerNet and fewer threads. For the most part, however, eight is the optimum.

toby
05-28-2005, 03:24 PM
Welcome to LW, it is the most enjoyable program I've ever used.

It takes a little time for LW to split data into threads, the more threads the more time. So generally the longer your render takes, the more threads will help you, but it's always worthwhile to do tests. Turn on 'show render in progress' and you can see the different sections rendered by each thread. If there's nothing to be rendered in some of those sections, multi-threading may take longer.

HV seems to take more time to split into threads, but in tests with several HV filling the screen, multiple threads rendered twice as fast as one thread, but with one HV, one thread can be 5 times faster - so tests are even more important with HV...

Ge4-ce
05-29-2005, 10:58 AM
I once wrote an explanation to this issue.

go to this forum thread (http://vbulletin.newtek.com/showthread.php?t=35198&highlight=Ge4-ce)


and see if it can help you out deciding the n of threads you need quickly

cheers,

Ge4-ce

Cinewalt
05-31-2005, 09:53 AM
Cool. I'll just test some stuff out.

Anybody know of a utility that will give accurate visual feedback on the load on EACH processor? Besides clocking renders, I'm just curious to see how much work LW is giving each processor in different settings including ScreamerNet.

Scazzino
05-31-2005, 10:07 AM
I use Activity Monitor's CPU history window...

-MikeS

Ge4-ce
05-31-2005, 04:04 PM
I downloaded temperature monitor from versiontracker. you can see by the temperature of you CPU how hard and 'if' it's working or not.

It also comes with a byte-counter. It measures how many bits and bytes pass the CPU/sec giving very accurate indication of how hard you processor is at work.

Best of all is the tread count divider. It measures how the threads are divided to each processor and therefore you can also see how hard each processor is at work.

This app is bulletproof... a must-have

avkills
06-05-2005, 01:45 PM
Well I am pretty confident that LW uses both processors the minute you choose more than one thread. About the only time my CPU fans kick in hard is when I am doing LW renders or playing system stressing games like Doom3.

So far I have found that just doing two threads works best for me.

-mark