Hey Deke, Could you elaborate on the last paragraph. Given a multi chan EXR. Are there bench mark tests that have been done to track optimal setups in comps? Basically, better to do this than that. I know there are a multitude of scenarios you have to consider but there are some tips users can supply based on their experiences.
I'd say submitting them in an email thread is probably the best approach or the Foundry can compile and validate the submitted tips. They're not busy working on anything at the moment, right?! ;-) On Thu, Sep 1, 2011 at 1:55 PM, Deke Kincaid <[email protected]> wrote: > Exr files are interleaved. So when you look at some scanlines, you need to > read in every single channel in the EXR from those scanlines even if you > only need one of them. So if you have a multichannel file with 40 channels > but you only use rgba and one or two matte channels, then your going to > incur a large hit. > > Another thing is it sounds like you are shuffling out the channels to the > rgb before you merge them. This also does quite a hit in speed. It is far > faster to merge and pick the channels you need rather then shuffling them > out first. > > -deke > > On Thu, Sep 1, 2011 at 12:37, Ryan O'Phelan <[email protected]> wrote: > >> Recently I've been trying to evaluate the load of nuke renders on our file >> server, and ran a few tests comparing multichannel vs. non-multichannel >> reads, and my initial test results were opposite of what I was expecting. >> My tests showed that multichannel comps rendered about 20-25% slower, and >> made about 25% more load on the server in terms of disk reads. I was >> expecting the opposite, since there are fewer files being called with >> multichannel reads. >> >> For what it's worth, all reads were zip1 compressed EXRs and I tested real >> comps, as well as extremely simplified comps where the multichannel files >> were branched and then fed into a contact sheet. I was monitoring >> performance using the performance monitor on the file server using only 20 >> nodes and with almost nobody using the server. >> >> Can anyone explain this? Or am I wrong and need to redo these tests? >> >> Thanks, >> Ryan >> >> >> >> _______________________________________________ >> Nuke-users mailing list >> [email protected], http://forums.thefoundry.co.uk/ >> http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users >> > > > _______________________________________________ > Nuke-users mailing list > [email protected], http://forums.thefoundry.co.uk/ > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users >
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