I'm not sure that's a Processing issue so much as a Java Virtual Machine issue.  Take a look at this thread.. little old but maybe it will provide an answer.
http://www.theserverside.com/discussions/thread.tss?thread_id=26347

Also, I don't know that Processing can utilize multiple processors... I think it's single threaded, unless you specifically create new threads.  So your supercomputer may not be any more powerful for Processing than a new 500 dollar desktop with a decent video card.  I could be wrong here though.

The question might be silly, but is your Windows Server Edition a 64bit system? If not, I think you are limited by the system.
The thread pointed out by jeffg is interesting, it shows there are many pitfalls at using lot of memory in (not so) old systems...

If your sketch isn't real time (unlikely with Sunflow, no?), perhaps you could compute smaller images by fragmenting the big one, then stitch them together.

You running 64bit Java?  It should work... Processing maintains it's memory setting in the preferences, by checking "Increase maximum available memory", which for windows just compiles essentially a batch file launching the jar file using the "-Xmx2000m", so you could play around with manually launching it to see if it changes anything.

I would move the topic to Integration, instead... But I doubt you will find a better audience.
The topic is interesting. Your config is quite rare, but multi-core processors become common and 64bit systems too.
I suppose Java is able to split tasks between processors automatically (is it). Explicit parallel processing is hard to do, lot of people study that but the topic is far from being extensively known...
That's why I think that moving the thread to Processing implementation wouldn't be useful, as I doubt the authors would spend time optimizing multi-processor work (unless they have personal interest on the topic!).

Note: as I wrote above, perhaps you can optimize the code yourself, spawning multiple threads dividing the rendering task, I think Java will spawn the threads on multiple processors.
Somehow, Processing is a "toy", optimizing rendering like you want would need a good level of Java knowledge...

I am not a specialist of the topic, alas. I know there are researches on the field (Java, multi-threading, multi-processors, clouds...), see for example Terracotta.

I have a friend that was having memory limitation issues on Java.  He switched to Oracles JRockit and it resolved them.  Not sure this is relevant but I thought I would mention it.

another maybe minor thing...

since i noticed that my opengl sketches didn't act nicely and were giving me 1/3rd of an image(in the form of a centered rectangle(all the rest was a black frame)), i found out that there is no opengl hardware acceleration if you run 32bit applications on 64bit platform for windows.
this is because in 64bit windows there is only an opengl emulator...

http://support.microsoft.com/kb/835563

so, i can use P3D or p5sunflow instead. on linux server i didn't have problems with opengl.

anyone running opengl on a windows 64bit machine?

best,
t

jeffg wrote on Feb 24^th, 2010, 5:48am:

I tried JRockit last week and hated it.