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R2018a_update3 (Linux) slow down MCT fft related functions
After installation of R2018a_update3 (Ubuntu 16.04 64 bit) was observed significant slow down of some MCT built-in functions (especially fft, ifft,fft2 and ifft2).
Answer
![](/s/cache/50/11/5011a676f5fcd364dcd8206a0a2a445b.png)
When re-apply all 3 available R2018a updates the situation is again normal ... now significant slow-down. Strange!!!???
![](/s/cache/33/eb/33ebcfe83a5428c0b237b4db844978aa.png)
I am not sure why this is happening.
But I suspect that freshly installed MATLAB might do some extra work in the background (building cache to speed-up startup time in future, or something similar). Do you see intensive processes in the background?
![](/s/cache/50/11/5011a676f5fcd364dcd8206a0a2a445b.png)
I have Matlab R2018a + update 2 working well with MTC. After install of R2018a_update3 I have got the above mentioned problem even after restart and Matlab warm up, so the cache should be already build. Then I reinstall all updates 1 + 2 + 3 again over this current Matlab installation and then everything works very well again.
![](/s/cache/33/eb/33ebcfe83a5428c0b237b4db844978aa.png)
I see, thank you for clarification. MATLAB is huge, maybe something went wrong during update.
But definitely, this it is not a toolbox bug :).
![](/s/cache/50/11/5011a676f5fcd364dcd8206a0a2a445b.png)
OK ... I am happy now :)
Just one observation: during this problem all cores (+ logical threads) were fully used when MCT fft related (fft, ifft, fft2, ifft2) functions was tested by mp.Test. But these functions was terribly slow (~100x slow down).
![](/s/cache/33/eb/33ebcfe83a5428c0b237b4db844978aa.png)
Yes, these functions try to use all available cores. If functions were slow - this means that other processes were intensively using the same cores.
![](/s/cache/50/11/5011a676f5fcd364dcd8206a0a2a445b.png)
This is what is the really strange ... there were no additional processes just MATLAB.
I think we can forget this strange episode ...
Customer support service by UserEcho
I see, thank you for clarification. MATLAB is huge, maybe something went wrong during update.
But definitely, this it is not a toolbox bug :).