686mhz

Hi guys Today i bought a new computer. The spec is Athlon 2 X4 630 Biostar TA785G3-HD Coolermaster 600w Zion 2GB DDR3 1333 I installed amd's Toverclocker and its showing my RAM's maximum bandwidth as 686MHz. Is this normal or should i be getting 1333MHz? Sorry if what i said is stupid. I...