Why are their several DDR3-1333 speeds?

[jaredudu]

I was looking on Newegg and saw their were 3 different types of -1333

DDR3 1333 (PC3 10600)
DDR3 1333 (PC3 10660)
DDR3 1333 (PC3 10666)

Does anyone know why, and also which is best?

 

[crazy pyro]

It's due to them all having slightly different speeds (as in they're all skewed slightly off 1333).
PC3 10666 is the fastest but there's a total of 8.25 MHz difference between 10666 and 10600.
To get the different bandwidths you take the speed and multiply it by 8 (usually 8 memory modules on the RAM stick is why I think).
Basically it doesn't matter, just go for the cheapest one/ the one with the best looking heatspreaders/ the ones with the best reputation for OCing.
Pyro.

 

[jaredudu]

Ok thank you very much