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View Full Version : Is Hypervoxels multi-threaded?



Meshbuilder
02-12-2003, 04:50 AM
Hypervoxels is really slow, even on a dual 1Ghz mac. Can one of reason be that hypervoxels isn't multi-threaded?

paintboy
02-12-2003, 07:16 AM
they seem to work better/go faster with 1 thread...give it a whirl
and see if this helps any(although you should not expect big gains)jus a little.
they are cool, but pokey...

Jimzip
02-12-2003, 05:24 PM
Yeah, one thing NT really have to look at is hypervoxels...
P.S. paintboy I really like that avatar!

NigelH
02-12-2003, 10:52 PM
Hypervoxels ARE multithreaded (believe it or don't). When the threads are set to 2, one processor handles the top half of the image while the other processor handles the bottom. When the camera's viewfinder is filled with hypervoxels, I've found that setting the threads to 4 or 8 gives the best possible performance because both processors are always kept busy.

Course, this isn't to say that Hypervoxels are fast, but they DO take advantage of both processors. Just, very slowly.

Meshbuilder
02-13-2003, 12:48 AM
Thanks NigelH. I really hope Newtek will speed up Hypervoxels and Skytracer for Mac in the next release..

anieves
02-13-2003, 06:55 AM
I read somewhere that HV weren't multithreaded and thus the reason they are so slow on the Mac. Now, I'm just not sure... I'll look into it and if possible find the place where I read that.

NigelH
02-13-2003, 07:15 AM
If you have a DP Mac, just check it out. Render some HyperVoxels and launch your cpu monitor utility. The cpu load is split up by percentage of the image rendered (8 threads will render 8 slices of the image at once, producing a kind of 'venetian blinds' effect). If HyperVoxels are only in the bottom half of your frame and threads are set to 2, then the top half will be rendered very quickly and that processor will idle away while the other processor struggles to complete the bottom half. In such a case, it's better to set the number of threads to 4 or 8 so that both processors will always have something to work on. So technically, the calculation of each individual 'voxel' may not be split between both processors, but as long as both processors are busy (nobody's laying down on the job), I'm happy.

anieves
02-13-2003, 10:50 AM
I have my Dual Mac set to 4 threads... I just have never looked into weather HV are multiT or not. I'll check it out when I get home.

Lynx3d
02-13-2003, 11:45 AM
PC version definitely is multithreaded, even in LW 6 ;)
Gives a nice almost 100% boost if it covers larger parts of the scene...

But HVs are just very heavy math...and for whatever reason it's not the favourite task of G4 (and Pentium4) CPUs (maybe someone knows Chris' LightWave Benchmarks (http://www.blanos.com/benchmark/))...seems it's nothing you can boost with Altivec and SSE2.

Tartiflette
02-16-2003, 07:30 AM
Hello all, I just wanted to tell you about a very strange thing :
I have noticed that the Variations scene is rendered a lot faster on Mac OS9 than on Mac OSX !!
For my system, the render time were :
Variations on Mac OS9 : 199.3 seconds with 4 threads :)
Variations on Mac OSX : 275.8 seconds with 4 threads :(

The system setups were :
PowerMac Bi-G4/867 with 768 MB RAM, the Geforce 4Mx, and for the system :
Mac OS 9.2.2 French edition (400 MB for LW7.5...)
Mac OS 10.2.3 with all the latest updates...

No other application were running during the test, except the services on Mac OS X, which was a fresh install...

Since I don't use Mac OSX right now, because I still prefer Mac OS9 and LightWave runs without any problem on my system, I just wanted to know if some of you here had noticed the same ?? :confused:

Thanks for he reply...

Laurent aka Tartiflette :)