Hi I have problems in running a parallel for-loop. The task manager indicates only 8% workload, showing that only one of the 12 cores is running. I need that for image processing of a directory of about 20 000 tiff-images (U16, greyscale) I first thought it is a problem of Vision-vis, as they use pointers as image references. Pointers would cause troubles in a parallel for-loop. Therefore I briefly rewrote the morphological filter vis without using the vis from the vision-toolbox. but it does not help. The programm is still running with 8% workload, indicating only 1 core is active. A small test showed that labview is able to run a task with all 12 cores. It is not a windows configuration problem. Maybe someone has an idea why this doesn't work so far. The main programm ist called 'StreifenWegmachenAlleBilderv11Multicore'. All other vis are sub-vis. At the moment it would take ~1 week to process all images. I want to speed it up for an overnight-operation. Greetings b

@Yamaeda wrote: GaussFilterOhneVision isn't reentrant, that'll effectively stop parallelization. Yes, the missing reentrancy is the main problem. You could even inline it. I also get more than 2x faster result by parallelizing the outer, instead of the inner FOR loop. (~ 1.2seconds on my 16 core Xeon) Have you tried the 2D convolution directly. Probably would save you quite some programming effort. Even has the padding built-in 😉 Also, your generation of the Gaussian kernel is a bit convoluted. You could use the outer product of a 1D gaussian. The results agree within ~1e-18 (see snippet, probably irrelevant after converting back to U16)

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parallel for-lopp configuration not possible

Solved!

@Yamaeda wrote:

Why wouldn't you just use 64 all the time (can the default be changed?) if it's the lowest of threads and this number ...

Well, each generated parallel instance is a code duplication, so it is also a matter of memory use. There is typically a sweet spot that gives you a good balance.

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parallel for-lopp configuration not possible

Re: parallel for-loop configuration not possible