Hi Everyone, I am using Boost Threads (1.38) as threading library and I also use the thread_specific_ptr to store a minor amount of data per thread (I think currently it is like 5 different pointer values per thread). Technically everything works out fine, but I am having a performance problem on Mac OS X. On Linux the performance is 10 times faster than on Mac OS. If I use pthreads on Mac OS I have identical performance to the Linux version. Both versions are running on the same machine using 8 threads both. Is there any known problem with shared pointers on Mac OS? I have tried different versions of boost, compiled it myself and also used macports - every time same results on Mac OS. Any hit or possible workaround is very welcome :) Thanks and regards, Oliver