[java-dev] Performance differences between Windows & Mac OS Jit/Java

This is a follow-up of sorts to my previous query about TCP & Java.

We (John Dekron and I) have a Jitter/Java based standalone which is supposed to run on a Mac Pro. The basic processing consist of jit.scissor-ing a 360x50 matrix into 8 parts, each of which is then sent by TCP to a custom wall-sized display using a custom TCP-based protocol. The app runs well enough when we only send a single portion of the matrix, but the CPU demand is pretty high. By the time we use all 8 TCP connections, our standalone is using 100% of its processor's capacity and we're down to about 9fps.

The thing is, if we boot the same machine into XP via Boot Camp, the Windows version of our standalone can handle about 20fps and Task Manager says it's using about 80% of CPU capacity (am I right in my understanding that Task Manager is talking total machine capacity, ie 40% of a single core?). 

In any case, we've got identical hardware, identical Java code, identical Jitter patch. So where does the performance difference come from? Are the JVMs so different? The TCP/IP implementations? Something else? My experience in Max/Jitter is that the OS doesn't make a big performance difference given identical hardware.

I'm attaching the .java & .class files if someone would care to look (Ben?). I know that I'm instantiating an InputStream that I don't really need (there was a lot of Copy&Paste to get this working at all) but I don't think that can be slowing things down. I'm wondering if there's anything I can do in my jit_matrix() method to speed up copying the Jitter data into our TCP packet data structure. The other obvious bottleneck is DataOutputStream.write(), but what can one do to speed that up?

If a test patch would help I'll cobble something together. The biggest problem in testing is that currently the only test hardware on the planet exists in a village outside Leipzig and is inside an intranet. Not an ideal testing environment? Tell me about it-(

Finally, before someone asks "Why not just use Windows?" the computer needs to run other processes as well as our standalone, and Mac OS is really what we need. 

Thanks for suggestions.
--
Peter Castine
--
Peter is in dire need of a new Facebook tagline. Not to mention a new .sig
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