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View Full Version : Does LW 9.6 utilize 4 cores or 8 cores?



virtualcomposer
04-17-2011, 12:58 PM
Does LW 9.6 even support 8 cores or does it just support 4?

wrench
04-17-2011, 01:35 PM
It will use as many cores as you have when rendering.

B

virtualcomposer
04-17-2011, 01:42 PM
It will use as many cores as you have when rendering.

B


oh ok. Well that sounds good. I thought LW only used up to 4 cores but I guess I'm behind the times. LOL

Sensei
04-17-2011, 08:48 PM
Of course we're talking about rendering..

Not modeling, or other things..

Silkrooster
04-17-2011, 10:46 PM
Man that would be sweet, if modeler could use all 6 cores in my system. Even though, I can load a mesh with over 2 million polys, just rotating the mesh takes forever(not literally, lol.).

rsfd
04-18-2011, 03:45 AM
afaik, 9.6 is limited to 16 threads (for rendering).
An 8-core with active hyperthreading would be 9.6's limit.

9.6.1's limit is actually at 64 threads.

Red_Oddity
04-18-2011, 03:51 AM
afaik, 9.6 is limited to 16 threads (for rendering).
An 8-core with active hyperthreading would be 9.6's limit.

9.6.1's limit is actually at 64 threads.

I doubt enabling hyper threading when doing rendering helps much (i haven't tested with LW, but for rendering in Mental Ray i did, and with MR it actually degraded performance when rendering), as hyperthreading only adds a virtual CPU/core with its own flow control, but both still share the same floating point processing resources.

JonW
04-18-2011, 04:37 AM
On my W5580 I did a few tests with HT off. I can't remember the exact speed but LW scenes rendered about 30% quicker with HT on.

rsfd
04-18-2011, 07:06 AM
@Red Oddity:
performance gains with hyperthreading are very app specific.
I just wanted to point out, that 9.6 is indeed limited to 16 threads, which makes it impossible to use the full capacity of e.g. an actual dual 6-core computer with HT enabled with LW9.6.

Red_Oddity
04-18-2011, 07:54 AM
On my W5580 I did a few tests with HT off. I can't remember the exact speed but LW scenes rendered about 30% quicker with HT on.

That's good to know, it's a shame though HT needs to be enabled/disabled via the BIOS.
We have it turned off on all machines now as MR has become our primary renderer (soon to be replaced by V-Ray)

virtualcomposer
04-18-2011, 09:58 AM
Well, I've decided to get the Mac Pro 2.8 Quad 2010 model and just amp up the RAM and maybe update the video card. It has an ATI Radeon HD 5770 so that should suffice for now. Even though LW can use up to 16 cores, I think it will still scream on the newest quad system. It was between the 2008 8 core machine 3.0GHz and this. Still a little up in the air about it since it comes with 16GB of RAM.

caesar
04-19-2011, 06:20 PM
On my W5580 I did a few tests with HT off. I can't remember the exact speed but LW scenes rendered about 30% quicker with HT on.

The HT performance is very app dependable, but high threaded apps in general are the most improved.

rsfd
04-20-2011, 03:44 AM
…Even though LW can use up to 16 cores,…

don't rush and mix "cores" with "threads" ;)
Even though it isn't that important in this case here, "core" and "threads" do mean different things, as one (physical) CPU (processor) nowadays can have multiple "cores" and one "core" can run up to 2 "threads".
As I stated above, LW9.6 with its 16 threads limit runs fine on hyperthreaded 8-core machines (= 16 threads), it will fail to use all available threads on a hyperthreaded 12-core machine (= 24 threads). This is where 9.6.1 or 10 should be used (64 threads limit).
(just a friendly reminder :) )