> article). I'm using RDTSC from user space since a while in a FFT > benchmarking software, i just wonder how it is possible ? > > my software can be found here: > ftp://sicel-home-1-4.urbanet.ch/pub/XSpectrum-1.1.tar.gz > > Needless to say that i own an intel pentium.
RDTSC access from user mode is controlled by one of the other magic control registers. See www.x86.org