Multi tasking discrepancy

[re:FORM]

Is there any reason why my dell M70 single core laptop can handle multitasking whilst rendering with vray far better than my quad core, dual 265 opteron system?
I was hoping the 4 cores would mean the os would handle multitasking with ease.... but the reality is that it kills the system speed until you drop the priority of 3dmax; something that I dont have to do on the m70.

Weird or what!
The opteron system is running windows x64 if that has anything to do with it.

[jacksc02]

what processor is in the laptop?

[re:FORM]

Its the 2Ghz Pentium M.

Its a great machine.... I recently did the cinebench test, and the opengl performance was better than the dual 265 with nvidia 3400! I guess the opengl performance( on the 265 system) suffers alot under the slower single thread performance.

[muzzy]

may be related to this

http://forums.splutterfish.com/viewt...0fc77f152b2145

directly from the link...

Hello all,

As you may or may not be aware, there appears to be an issue in 3ds max r7 and r8 where certain components leave the 3ds max state set incorrectly - causing one or more of the CPUs in a machine to fluctuate in performance.
This tends to affect elements of 3ds max and third party plugins which are highly threaded; Brazil r/s is such a third party plugin, and the effect of the issue is essentially that a dual (or higher) processor machine, such as AMD Opterons, may render at a lower performance than it's capable of.

Although this issue has been confirmed by many users of the 3ds max software, a fix for this issue has not yet been provided.

A laborious fix exists by manually setting the processor affinity mask for the 3ds max process to include all processors, after 3ds max has finished starting up. As mentioned, this is rather laborious - and also infeasible on network renders.

With the help a few of our forum members and betatesters, we (I) have written a solution to this problem by automatically re-setting the affinity after 3ds max starts up. Essentially this is done through a MaxScript which is run after 3ds max starts up, which in turn calls a third party MaxScript extension (by Larry Minton of Avguard Animations) which contains the affinity mask modification capabilities required.

[re:FORM]

I was aware of this... but my problem isn't that the renderer is not making full use of the processors, its that the renderer is leaving the OS with no processor cycles to do anything.... it takes 20+ seconds to get the task manager up after I hit render sometimes. I never have this problem with the M70.

[mike.edel]

i guess you should be lucky that your system gets used so effectively

after all it just means every bit of computing power gets used up rendering instead of being reserved for the OS

if you need to work with other applications/the os while rendering in the background you should indeed lower the process priority for max/vray

there really is no catch in it (if you don't need any cpu cycles for something else, the cpu will still be used for rendering 100%)

btw: you can lower the priority before submitting the rendering using the vray system rollout (low thread priority)
http://www.spot3d.com/vray/help/VRay...ams_system.htm

btw: i guess the reason for better multitasking performance under full load lies in the fact that laptop processors have to be able to pause and resume processes in order to save energy
the architecture of the pentium m is vastly different from the opterons (it's remotely based on a pentium 3)

[re:FORM]

Mike,
Thanks for that. Very interesting. I guess that makes sense. I totally overlooked that option in the vray settings.

I'll see if that sorts things out when I get a chance tomorrow.

I know its easy enough to drop the priority in the task manager, but its easy to forget to do it, and I find it a real pain when the system slows to a crawl. I often get down to other things when I send a render, and hoped the 4-cores would make this kind of multitasking a breeze.

I was beginning to think it was a problem with win xp64... hopefully the vray thread priority will sort it out.

[RErender]

There are some scripts on www.scriptspot.com that will allow you to preset max to start at whatever priority you wish.

[re:FORM]

Thanks guys. Those scripts have made the world of difference.... I'm now getting the smooth multitasking I was expecting to get