I've a dual Pentium III (with Streaming SIMD Extensions)and I've tried compiling code with these instructions enabled using the Intel C Compiler v 5.01. The optimizations string is:
/G6 /Gr /MT /W4 /Ob2 /I /QxK
The odd thing, it runs slower (!). Considerably slower than when I leave out the /QxK.
Clearly I'm going wrong somewhere. Any pointers?