Slow Parallel Computing in Grasshopper

Hi Everyone,

I have a AMD Threadripper 1950x (a lot of cores). In almost every native grasshopper component which supports parallel computing I get slower times than using single thread computing. Has anyone else had these problems? This is not definition specific.

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Intel 6/12 here. Same experience.

Threading typically takes testing to see if it adds any performance gain. If not, shut it off. For this reason I have suggested that default should be off.

// Rolf

Yes, I agree default should be off until its more reliable. I would say that 90% of the cases PC isnt the best option.

It’s not about reliability. Threading does what it does, but threading isn’t always faster, which is why one have to test if it is, and if so, turn it on.

// Rolf

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Also note,

Multi-threading has set up time before computing. Speed is usually slower with less processes because that initialization time is added. After the initialization it is usually faster on the actual processing of the items, that is why multi-threading is usually faster with many processes.

So say in multi-threading initialization takes 5 seconds, and then the process of 3 items takes 2 seconds. That is 7 seconds total.

Say the same 3 items processed not multi threaded takes 5 seconds (slower than the 2 seconds of the multi-threaded version) but it doesn’t have the initialization time, so total time is 5 seconds. Faster time overall than the multi-threaded.

At some point of processing many items, multi-threading will be faster overall when initialization + processing is less time than non multi-threaded regular processing.