Ater a quick test with these different compiler options:
MSC8 -> -O2 -GS- -arch:SSE2 (with and without this one)
MinGW -> -O3 -ffunction-sections -msse2 (with and without this one)
And found this:
using -arch:SSE2 on MSC gave me a 1.75% speed boost
using -msse2 on MinGW gave me a 2.47% speed boost