25% cpu usage during LC and IM prepass calculations!

[jacksc02]

keep upping the dynamic memory until it crashes then back it off 100mb and use that

[panthon]

I really appreciate the time you are spending to answer me jacksc02! Thanks

[jacksc02]

no worries, msn me if you want

yay that was my 1100th post

[panthon]

I guess im going to give up. It´s too random to narrow it down.

I´ve tried upping dynamic memory till it crashes and lowering it down with no success. Static didn´t help either.I´ve tried locally and remotely, with show precalculation phase on and off, even with virtual frame buffer on and off, vray framebuffer on and off, render to memory on and off.

The only thing which helped was disabling all vraydisplacement mods, so i´ve changed them into displace mods and now it´s rendering at 100%. Some things cannot use displace modifier because of the insane amount of polys they would require to render correctly, like grass, but most of our organic objects can do quite well with it. It renders faster and uses less memory...

[jacksc02]

panthon, all i can suggest to you now is to do your lighting calculation without the displacement and then render then try and render the final frames with displacement on

[panthon]

panthon, all i can suggest to you now is to do your lighting calculation without the displacement and then render then try and render the final frames with displacement on

I´ve done it several times, but for some reason it´s not working. I precalc without displacement at 100% but when render starts it drops to 25%. I´m suspecting it´s not rendering at 25% speed either, it´s much slower, quite maxwelllike. It looks like vray gets stuck in some places doing redundant calculations, which, on top of that, don´t seem to be multithreaded, specially through refractive wine glasses. I will show you the test animation i´ve rendered replacing all the vraymods if u want. That would make it much clear...

[throb]

Re: 25% cpu usage during LC and IM prepass calculations!

Hello!

We are facing a problem here with our scenes only taking a 25% of cpu power when rendering via backburner and locally. We have dual xeons with HT enabled and 2 GB RAM.

Is there anything we could do? These render times are killing us!

the thing i ran into with this is that i had to force vray to render on multiple procs (threads really) and then it was perfect.

to force it do this with maxscript
vr = renderers.current
showproperties vr

(this will get you all the vray maxscript things)
there is something in the system options that has something to do with numthreads. set it to 4 and you are good to go.

rob

[RErender]

Re: 25% cpu usage during LC and IM prepass calculations!

Hello!

We are facing a problem here with our scenes only taking a 25% of cpu power when rendering via backburner and locally. We have dual xeons with HT enabled and 2 GB RAM.

Is there anything we could do? These render times are killing us!

the thing i ran into with this is that i had to force vray to render on multiple procs (threads really) and then it was perfect.

to force it do this with maxscript
vr = renderers.current
showproperties vr

(this will get you all the vray maxscript things)
there is something in the system options that has something to do with numthreads. set it to 4 and you are good to go.

rob

That is the same as?

Check the << Number of passes >> in the LC rollout...
Should be 4.

Best regards,
nikki Candelero

[vlado]

If you have a lot of displacement and you have specified too low dynamic memory limit, you are forcing V-Ray to thrash and re-create displacement geometry on the fly way too often. For many reasons, operations like creating and flushing geometry are not multithreaded. This would explain the performance drop. Increasing the dynamic geometry limit will probably help, but at the expense of more RAM while rendering. Another solution would be to increase the Edge length for the displacement, which will reduce the memory required by displaced geometry.

If you have the Bitmap pager on, and you have many large textures, this may also cause 3dsmax to swap textures in and out of memory too often, which will also result in poor performance.

Yet another reason for the performance drop could be if you have too little physical RAM and Windows has to swap chunks of memory to disk.

Best regards,
Vlado

[panthon]

Another solution would be to increase the Edge length for the displacement, which will reduce the memory required by displaced geometry.

If you have the Bitmap pager on, and you have many large textures, this may also cause 3dsmax to swap textures in and out of memory too often, which will also result in poor performance.

Yet another reason for the performance drop could be if you have too little physical RAM and Windows has to swap chunks of memory to disk.

Best regards,
Vlado

I´m going to increase the edge lenght and see if it works. Our render nodes have 2 Gb RAM, but we will be testing some 3 or 4 Gb RAM on Windows 64bit. maybe it helps. In the meantime, we just switched displacement, from vray displacement mod, to displace common modifier.
Thanks for your answer, Vlado.