hardware - Low memory bandwidth -

i have ddr2-667 ram , measured memory bandwidth via stream tool.

here results:

function     rate (mb/s)   avg time     min time     max time copy:        2229.0490       0.0158       0.0144     0.0206 scale:       2208.1095       0.0160       0.0145     0.0216 add:         2620.2118       0.0196       0.0183     0.0208 triad:       2358.1446       0.0217       0.0204     0.0246 

but theoretically memory bandwidth 5333 mb/s.

why bandwidth results low ? there solution increase (e.g overclock)

first, samgamgee said, reaching theoretical memory bandwidth hard.

using multiple threads could increase measured bandwidth, though. stream default disables multi-thread support, though. can enable adding -fopenmp (if using gcc) compile option enable multi-thread support.