MATLAB Answers

adding breakpoint to program slows it down a factor of 250x

19 views (last 30 days)
gkk gkk
gkk gkk on 18 Dec 2012
I observed this in a larger program, then created a simple test case to ask this question.
The following program takes 0.038 seconds to execute without any breakpoints.
tic;
for ii=1:16000000
xyz=1;
end
toc;
z=1;
But if I set a breakpoint at the line of code for z=1, it takes 9.3 seconds to execute.
Is this normal? Is my system corrupted somehow? Any feedback much appreciated.
Rebooting the computer doesn't make a difference. I have 32G of RAM available so that shouldn't be the problem. Not sure what other knobs are available to try to get better performance.

Accepted Answer

Matt Fig
Matt Fig on 18 Dec 2012
It makes sense to me that MATLAB would be slower when you are debugging. So what is the big deal? You won't be in debug mode once the program is ready for use, will you?
  9 Comments

Sign in to comment.

More Answers (1)

Teja Muppirala
Teja Muppirala on 18 Dec 2012
Might I suggest using the KEYBOARD command? It's a bit simpler than setting up dbstops and trys and catches, and works just as fast.
tic;
for ii=1:16000000
xyz=1;
end
toc;
keyboard;
z=1;

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!