View Full Version : RAM for Nodes

09-06-2006, 04:43 AM
Do screamer net nodes need the same amount of RAM as a single machine for rendering scenes? I am assuming yes since they need to each load the scene and the associated image maps.


09-06-2006, 07:07 PM
Ummm, bump.... anyone... Bueller?


09-06-2006, 07:18 PM
They need a bit less, especially compare to LW9.0 Layout, which needs a bit more memory for the OpenGL VBOs (if they are activated).
As a rule of thumb, start with one GB per node, and try to keep them at roughly 1GB less than your workstation. Your mileage may vary though.


09-06-2006, 09:08 PM
Yeeks, I have 5GB in my G5. If I add the memory for my images and how much the scene takes to render and maybe add some, you think I would be safe?

I guess Layout uses a lot of memory for making OpenGL image maps for OpenGL previewing also, so I may be good with only 2GB of RAM per node. Any quick and dirty ways to find out?


09-06-2006, 09:41 PM
It also depends on how many CPU's or cores your nodes will have and how many instances of LWSN you will run on each machine.

When using a dual processor Mac with one LWSN instance set to 2 or more threads, that one instance will be able to use up to 4GB RAM and both processors. If however you run two LWSN instances each set to 1 thread, then each instance can use up to 4GB of RAM and its own CPU.

So if you have 4GB or less on a dual processor machine and your renders only need 1/2 or less of the available RAM, you can run two instances of LWSN for maximum speed at one thread each. If however you are rendering something that requires more than 1/2 of your RAM you can run one instance of LWSN with multiple threads and it'll have access to all the RAM and both processors.

I find dual processor Macs to be extremely flexible in this regard. If I need to render high res stills that need lots of RAM I can run one LWSN on each machine using all the RAM and CPUs. When rendering DV resolution animation that may not be so RAM hungry, I can run two LWSN instances on each machine using 1/2 the RAM and one processor each.


09-06-2006, 10:10 PM
so I may be good with only 2GB of RAM per node. Any quick and dirty ways to find out?

That should be fine, unless you're working with very large scenes or very high resolution. I'm currently rendering my DV resolution digital short, BlastOff! (http://dreamlight.com/insights/12/welcome.html), on a render farm with a number of dual processor G4's each with only 1.75GB. I'm actually running two instances of LWSN on each machine. When I need to render high resolution or larger scenes I'll run one LWSN on each machine instead so it can use all the RAM. My main workstation is a DP G5 with 4GB of RAM.

You can run some tests on your G5 by doing a standalone render with LWSN on your G5 and then run the Activity Monitor to see how much RAM LWSN is actually using to render one of your typical scenes.

Here are some instructions on doing an LWSN standalone render.
Standalone Rendering with LWSN Mac: (http://dreamlight.com/insights/10/standalone_rendering.html)
Mastering LightWave ScreamerNet for Mac OS X (http://dreamlight.com/insights/10/welcome.html#top)

Another useful utility is MemoryStick (http://www.tidbits.com/matt/[email protected]@) which you can leave running on your render nodes. You can set it to display RAM stats as a bar graph and beep any time the Mac pages RAM out to virtual memory on the disk. So if you're rendering a scene and notice all your nodes beeping, it means you could use more RAM (or switch from two LWSN's per Mac to one LWSN per Mac if the nodes are dual processors).

I've enclosed a snapshot of my Activity Monitor which shows a single LWSN instance set to 8 threads running on my dual processor G4 at home which is participating in my studio renderfarm, over the Internet. It's currently only using under 600MB of RAM...


09-07-2006, 12:11 PM
Thanks for the info. Basically I have the hi-res photoreal earth, which is using around 650MB+ of image textures, plus when rendering it takes up about 500MB, due to using APS, so it is around 3 million polys.

I am just thinking about making a custom made cabinet that I can slide PC Mobos into, so I can expand when needed. I am thinking about Core 2 capable boards that support at least 4GB of RAM. It is just an idea at this point.


09-09-2006, 11:40 AM
to test it, run BG Render (http://jezza.lwidof.net/lscript/#bg_render), close layout, and monitor your memory usage as the image or scene renders.

(if you're using LW 8.5 or below, backup your configs first. LWSN overwrites them wrongly and messes things up. LW 9 doesn't have this problem though.)