Changing the number of CPU makes no difference


I was looking into making the daylight calculation a little bit faster.
For a simple shoebox with 66 sensors and radiance parameters of -aa 0.1 -ab 6 -ar 256 and -as -ad 4096, it takes 1 hour ( I have also shadings) in a i7 laptop.

What I cannot understand is why, although I change the numofCPUs parameter, It takes the same amount of time for the analysis. In other posts I saw that if you input the maximum number of CPUs the calculation may take longer (that is also my case), but anything regarding what is happening to me.

Any suggestion is welcomed!
Best regards,


See this: Multithreaded Daylight Simulations

I’m currently working on a docker integration to help users to use Radiance’s inbuilt parallelization to address this issue. It’s not fully ready to use right now but you should keep an eye on the repository.

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