Re: [Boost-users] Xcode - Slow

On 30 Jun 2010, at 16:55, Raphaël Amiot wrote:

Hello there.

I am implementing matrix multiplication and am trying to have my stuff run as fast as possible. But then I noticed something strange. Using Xcode,

resultmatrix = prod(matrix1,matrix2);

is 10 to 16 times slower (with 100x100 matrixes) than simply doing something like that:

for(...) for(...) for(..) multiply_things();

And 20 to 40 times slower than a simple threaded approach.

Using visual studio, it's 2 times faster than naive multiplication.

This is on a release build, with #define BOOST_UBLAS_NDEBUG 1 #define NDEBUG 1

So what gives?_______________________________________________

Could you provide a small complete program which shows your problem? Chris