Hi, I am trying to compare RML vs RTL performance on a 3GHz x86_64 . The result I got for RML is 1260 ms (see below). The result greatly varies with the compiler optimization. Not sure what was Calum's 1.7GHz environment (his result was 1687ms) without optim. --> 21230 ms g++ -O2 --> 3200 ms g++ -O3 --> 1260 ms (see below) Arkadiy, I would need your latest realease so that I can compile it against boost head (I d/l your library from the vault, pls see compile error below. I also made some changes to compile in Linux) Regards, Jose =========================================== RML 1000000 ((0),(0)) ((1),(1)) ((2),(2)) ((3),(3)) ((4),(4)) ((5),(5)) ((6),(6)) ((7),(7)) ((8),(8)) ((9),(9)) Total 10 results 2000000 That took just 1260ms =========================================== g++ -O6 arkadiy.cpp -o test2 -Irtl -I/usr/local/include/boost-1_33 -L/usr/local/lib rtl/identifiable.hpp: In member function 'unsigned int rel::identifiable::id() const': rtl/identifiable.hpp:22: error: cast from 'char*' to 'unsigned int' loses precision make: *** [test2] Error 1 ===========================================