View Full Version : Multi-Threads?

10-09-2003, 02:54 PM
Hey Guys,

Last night I ordered my G5 dual 2ghz from apple! I should get in 7-10days.
I can't wait to finally work on a real machine! I have used Lightwave on a g3 400mhz and an imac g4 1ghz. Also, I'm sad to admit that I have worked on devil boxes (PC's) for too long. (just a harmless joke, I don't want to start some crazy PC vs Mac bashing thread :-)

Anyways I do have a question. I never understood the multi-threading option in the Render Options window. I noticed that it goes to 8 threads. If I am using 2 processors, would that be 2 threads? Why are there 8 different thread options?
How do I know what to set?



10-09-2003, 04:47 PM
Well one could have more then 2 CPUs...ever thought of that ;)

But actually, you most likely will see the best results with 4 or 8 threads even on a dual machine, simply because LW splits the frame into equal stripes for each thread, and if one thread (e.g. the stripe) is finished first you're left with one thread less etc until you're left with a single thread, so one CPU will run out of work sooner than the other, unless alle stripes need exactly the same time to render (pretty unlikely...)
With 8 threads there are usually at least 2 threads until most of the pixels are rendered.

This actually doesn't apply to many other renderers, many scanline renderers will just give the CPU without work the next scanline, or bucket renderer do the same with their buckets, and Cinema4D splits the image like LW, however if one is finished the rest gets split again.

10-10-2003, 06:50 AM
Great! Thanks for the info. You know, come to think of it, It never crossed my mind that you could have more than 2 processors.

Thanks a lot,