Render window faster than a batch sequence, why?

[jtk77]

Ok, I have a scene that renders in the "render window" option at about ..6 mins.
When I do a batch render..the same frame takes 20 mins. Whats going on here? Is the batch render more intensive?
I was curious as to the different in time here becouse its hugh. Its be tenius , but fast to just render each frame from the render view and save them. HA, I don't think I'll be doing that, but if I had to save 10 mins a frame I might.
Any ideas >?

[gmask]

I think it's because whne you render in the rnderview it's sharing th ememory resources allready loaded. Whereas when you batch render everythign has to be laoded into ram and tesselated etc. The following frames after the first should take much less time.

[trthing]

There's this Tabuchi Render view render MEL script that would take care of the render through the render view issue for you...
However, if you are Batch rendering through Maya's interface (not command line) in windows, maybe the reason is that the batch render task is getting a "background" priority while Maya, the application, is getting a "foreground" priority. That is probably the reason why you are still able to work in Maya while batch rendering.

[jtk77]

the comand line render is what it is. I tried the batch render with maya open and it seemed to be even faster but no where near as fast as the render window view.
The command line render seems slowest of them all and its really confusing to me.

[trthing]

That is weird...
Looking into the Processes' priorities in win2k (Ctrl_Shift_Esc//RMB over each process): Maya and MayaBatch are set as Normal (didn't try command line). When I switched MayaBatch to High it made a real difference in rendering times (it goes back to Normal in the next batch render, automatically).
I didn't address the foreground/background issue yet, though...

Actually, it did NOT make that much of a difference (-1 sec on 44 sec/10 frame total rendering time)

[jtk77]

A friend of mine suggested that the issue might lie in the fact that I am using a hyperthreaded chipset with win2k and have hyper threading turned on. He suggested that it can acualy slow your over all rendering under 2k?
Any truth to that? I am going to turn off hyperthreading in my Bios anyway to see.

[ferreel]

I've observed the same thing.

The scene I'm working with is using motion blur. I noticed that the delay is occuring during the sub-frame calculations (15secs vs. 4mins), while the actual rendering times are almost identical. Memory usage seem the same also.

I've tried upping the priority to no avail. I'm using win2k, so hyperthreading has been turned off.

ferreel

[jtk77]

not certain yet, but things seem to be less cagy at the moment with the hyperthreading off in win2k.
More than a few people who seem to know a good deal about what theya re talking about have told me to only use hyperthreading with XP.
The damn 3 gig chip still sails.

[joojaa]

back at work again

Ok just as ive allways supected (and veriefied some times)... hyperthreading is not good for calculation intensive tasks...

You se: If you only have 1 proc. But maya asumes you have two maya will split u its operations in therads... Now while this isnt bad in general it might be in this case because the proc is still not faster then 1 proc (t might virtualy sometimes be however depending on task). Now maya might be forced to wait for a thread wich was prcocessed by the other proc... Wich isnt true its tha same damn proc its just doing things in non logiclal order.

Also priorities go into play much more in multiproc environs.

And the defalt behaivour in windows is to boost the foreground aplication (wich is why your renderer is faster inside maya). Turn this off and tehn re test. The problem is that windows might be boosting soemthing over your priority... Wich can mean that maya gets most stuff chunked in the wrong way or something...

[ferreel]

Tested the same scene with WinXP (hyperthreading enabled) and got the same results.

However, noticed something very interesting. This may or may not be your problem. I noticed that on every frame Maya was rendering with mayabatch, it was performing a particle run-up from frame 1. Thus, for every frame rendered, Maya was calculating every previous frame again, and again and again. This did not happen in Render View. Setting Particle visibility to off, didn't fix the problem. However, setting the isDynamic attribute to off did. Now the command line batch render works just fine.

I guess motion blur, particles, and mayabatch rendering don't mix. (Even if you aren't rendering out any particles)

Regards,

ferreel