[Peter_K]

Ok, since there is a hd option to let you render out high-res images.. Wouldn't it be a good idea to incorporate this technique when rendering on a still image on several CPUs aswell?!

Now, when I do a 12 CPU rendering on a still image, the end result aint much different than if I would use only 1 CPU. I guess the blending between different .mxi image doesn't work too well..

Wouldn't it be much better, if for say every CPU render a slice of the image instead? Like when using 10 CPUs when doing a 2500x2500 image, would mean every CPU would render out a 2500x250 image instead, and then link together the different slices?!?

/Regards Peter K

[Mihai]

This has been discussed I think, and the problem is Maxwell needs to calculate the whole light energy propagation in the whole image, so you can't split it up. You should be getting a pretty big difference in time for 12 vs 1 processor....Are you sure everything is working ok? Are you comparing for example how long it took 1 proc to reach 22 sample levels, and then doing the same for 12?

[Peter_K]

Everything is not working ok..

Here´s a little simple test..



Its exactly the same scene.. First I´d let one CPU run for ten minutes it reached level 15.. Then I re-run the scene adding a CPU for each try. You can clearly see that 2 CPUs is different from one CPU.. Now when I let all twelve computers run for 10 minutes each, each CPU reaching level 15, the image is exactly as when running 2 CPUs.. Either its just a bug, or the way it combines MXI files just doesn't result in a better image.. I´ve created the scene in LW btw if it helps.. Would be nice to see if any other user get the same result..

/Regards Peter K

[Mihai]

After the mxi's from all 12 are combined, what's the total sampling level reached for the combined mxi?

btw, I can't see your image...

[Peter_K]

Just fixed the image.. I can't see any info when linking the image what sampling level its reaching.. It doesn't say :/

[Mihai]

I haven't done any cooperative rendering yet, I don't remember where that sl is shown (if it's shown at all), but are you sure you are specifying the correct number of threads when using the 12 processors?

I compared your 2CPU image with the 12 cpu in PS, they are identical - to the pixel. So obviously something is wrong with your cooperative render setup, or you are not actually opening the combined image file. Please post in the Maxwell forum, someone else will be able to give you more specific advice, for free!!

[Peter_K]

Ah, you where right Mihai! I´ve forgot to set the th:12 command line in the mxc file

Now it works definitly better.. I'll post another update comparing 12 CPU running for 20 minutes, compared to a 240 minute render on one machine and see if there is any difference in quality..