In our sessions, we have taught you to how to use the PSDK compiler and the compiler included with Visual Studio 2005. The Intel sessions have also taught you how to use the Intel compiler and many have asked me lately why would someone use the Intel compiler given that there is a Microsoft C/C++ compiler?
First off, do not think of the Intel and Microsoft compilers are mutually exclusive when it comes to writing code for the EM64T or the Itanium. The libraries and even debugging tools that are generated by both compilers can be used interchangeably without any problems. That being said, you may now start to think that these two compilers compliment each other instead of compete with each other - this is the mayor key giveaway that we want to teach during our sessions.
If you are ever working with matrix multiplication or code that has to do with products between arrays, you might want to give the Intel compiler a try. It can easily vectorize your loops and you will be taking advantage of the 16 SSE3 registers that are now available in the EM64T. Furthermore, if you need to write inline assembly in code that will compile for 64-bit, the Intel compiler will allow you to do this as well.
Hopefully this will clear some doubts...remember, you can use both compilers to your advantage and make them work together so that your code will run a lot faster than it did before.