Matlab vs. Octave

[Eduardo Gallestey]

Hallo,

in the application I am working on (PDE solvers), I must solve a system
of typically 2500 ordinary differential equations. Although my PC is
fast (PII 400 MHz), the code I have written using Octave's "lsode" is
rather slow (some hours !). 

I assume that, among other things, this low performance has to do with
the fact that the RHS of my ODE's are written in the Octave's "script
language", and not just as C++ dynamically loaded functions.

My first question is:

1) is that low performance of the script language characteristic for
Octave ONLY, or is this phenomena present in Matlab too? Should I expect
the same performance if I migrate my code to Matlab? Note that I
wouldn't like to do it for at least one thousand of reasons!

The second question is just a technical one: 

2) how do I pass global variables of the Octave environment to a
"dynamically loaded C++ function"? 

Thanks for your help,
Eduardo