Why does BENCH run slower in a newer version of MATLAB than it did on the older version?

Bench shows greater execution times for some functions when run in two different versions of MATLAB on the same computer.

Exact Steps and Code to Reproduce Issue: ran bench, then bench(10) under both R14SP3 and R2006a

Here are the results from bench:

7.1.0.183 (R14) Service Pack 3

0.2389 0.4370 0.2696 0.5002 1.4096 1.0373

7.2.0.30241 (R2006a)

0.2448 0.4445 0.9082 0.3239 1.6147 1.2123

Output of VER:

-------------------------------------------------------------------------------------

MATLAB Version 7.2.0.30241 (R2006a)

MATLAB License Number: DEMO

Operating System: Mac OS X Version: 10.4.4 Build: 8G32

Java VM Version: Java 1.4.2_09 with "Apple Computer, Inc." Java HotSpot™ Client VM mixed mode

-------------------------------------------------------------------------------------

MATLAB Version 7.2 (R2006a Prerelease)

Optimization Toolbox Version 3.0.4...

Answer 1

[MathWorks Support Team]

BENCH is used to compare the performance of the same version of MATLAB on two different machines. BENCH is not intended to compare two different versions of MATLAB on the same machine. For example, it is possible that some operations in MATLAB 7.2 (R2006a) appear slower than MATLAB 7.1 (R14SP3) because the BENCH command accomplishes a different task or number of tasks in various versions of MATLAB.