MATLAB: MATLAB 2013a. Performance issues. “Fast/new PC” perform worse that “slow/old PC” using same script on same data

Question

Hello,

Recently people in my laboratory have observed a huge performance loss on the "good" computers that we use for running big calculations. Our fast computers (attached dxdiagPC2 and dxdiagPC3 (16gb Memory, Intel i7 3.40Ghz, 8 CPUs)) are performing much worse than our older PCs (attached dxdiagPC1 (8gb Memory, Intel i5 3.40Ghz, 4 CPUs)).

Using the exact same script and data with MATLAB 2013a 64bit on all 3 computers I get the following elapsed time for each session:

PC1: 212.703871 seconds.

PC2: 1858.790018 seconds

PC3: 3119.389738 seconds.

Running the "bench" command scores PC2 and PC3 higher than PC1.

Similar time differences have been observed using different other scripts not related to the one used for testing here.

Also tested MATLAB 2014a 64bit on PC3 with similar slow result. UPDATE: Also tested MATLAB2015a 64bit on PC2 with similar slow result.

We have noticed this performance drop over the last month.

It would be much appreciated if anyone could help us on solving this issue or come up with an explanation to why our more powerful PCs are suddenly performing much worse than our older ones.

Best Regards,

Joachim

Answer 1

Using the "profile" command it was found that the "path" command was using up most of the time on the 2 slower computers. Changed the script to ignore this command fixed the problem and the script finished in the time expected.