## sensitivity analysis (vensim)

### Re: sensitivity analysis (vensim)

I ran the model on a super computer but since this version does not do any parallel multicore computation, the running time did not reduce. Do you have any plan for releasing that experimental version?

### Re: sensitivity analysis (vensim)

We're working on it, but I'm not sure whether it'll be done by end of year. The speedup is more than noticeable if you have a many-core machine. Older workstations with 16 or more cores are now readily available at dirt cheap prices. We'll keep you posted as this evolves.

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### Re: sensitivity analysis (vensim)

Thanks for your information.tomfid wrote: ↑Mon Oct 14, 2019 5:24 pmWe're working on it, but I'm not sure whether it'll be done by end of year. The speedup is more than noticeable if you have a many-core machine. Older workstations with 16 or more cores are now readily available at dirt cheap prices. We'll keep you posted as this evolves.

### Re: sensitivity analysis (vensim)

Hi,

I did Monte carlo Simulation for a large-scale model, after many simplifications in my model I got this error (it happens at Sensitivity Simulation 1/3):

I was wondering is there any solution for it or is it related to size of model?

I did Monte carlo Simulation for a large-scale model, after many simplifications in my model I got this error (it happens at Sensitivity Simulation 1/3):

*error writing results-disk may be full*I was wondering is there any solution for it or is it related to size of model?

### Re: sensitivity analysis (vensim)

Any chance that the disk really is full (or would be, after writing the results)?

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### Re: sensitivity analysis (vensim)

Are you using 32 or 64 bit Vensim? If you do a run with only 1 sensitivity instance (if you can), how big is the file size increment over a non-sensitivity vdf file?

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### Re: sensitivity analysis (vensim)

Actually, I see that the error happens on sim 1. Looking at the code, the counter for writing sensitivity result blocks is an integer, which will impose a 2 gigabyte limit per simulation. Any chance you're near that?

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### Re: sensitivity analysis (vensim)

I am using 32 bit now. The problem occures when I increase number of iterations. I think your assumption is correct, when size of vdf reaches 2 Gb it produces that error.

### Re: sensitivity analysis (vensim)

Can you increase the SAVEPER or thin out the savelist a bit? If you're getting gigabytes of output from a one or two simulations, it'll be pretty unwieldy when there are many.

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### Re: sensitivity analysis (vensim)

Sorry for late response. Actually, I used increased version of SAVEPER. For my case, as long as the model is huge (simulation of compiled version takes around 20 minutes) implementing Monte carlo and stochastic optimization is a big deal in Vensim.