Matlab 2013b simulation running slowly on one machine, but normal speed on the other.

Hello. We have a simulation running in Matlab 2013b that performs differently on different machines. The PCs use the exact same hardware, however. On the first PC, the simulation finishes in around 1.5 seconds, while on the second PC the simulation finishes around 7.5 seconds. Does anyone have an idea as to what would cause this? Please let me know what additional information anyone needs.

[José-Luis]

Do you have the same processes running in both computers? If you have malware in one of them, that is bound to slow it.

Try looking at the task manager in both machines. If one has 100 processes running and the other 40, you'll have your answer.

[David]

As far as I can tell, there isn't any malware on the slower computer. Scans reveal nothing, and the Windows Task Manager indicates only 20% of the computer's 6 GB of RAM is in use before running the simulation. There aren't any processes running that are using a lot of CPU time. There should be plenty of resources available for the simulation.

[José-Luis]

The amount of RAM used might not be the bottleneck. What about the number of processes? Maybe one of the computers has a very fragmented hard drive.

Are you sure it is the exact same hardware? Not all RAM is created equal. Access times might differ from hard drive to hard drive.

[David]

The simulation files being run are accessed from a network drive, so that's not the issue. There are only 65 processes running on the slower machine, while on the machine where the simulation is faster, there are 105 processes. The PCs are both the same model PC.

[José-Luis]

Then the network access times might be the issue. Is the slower machine behind a tougher firewall or has an antivirus program runnning?

[David]

Well, the issue was the connection between the network drive and the slower machine, somehow. The connection should be the same, but I guess it's not. Moving the simulation to the local hard drive solved the issue.

EDIT: Never mind. I was given some incomplete information. The simulation is only slowing down when a UDP connection is made to another machine running the actual flight sim.