Question about DDR memory stick numbers...

[dave4shmups]

So when I look at DDR3 memory sticks, there's always a hyphen, and then a number like 1600.  What does 1600 mean, in terms of the memory?  Does it have something to do with data transfer speeds?

[FloRolf]

Yes, it's the frequency which directly translates to transfer speed.

[TheRandomness]

1600 is the speed at which the memory runs in MHz. This is double the frequency it actually runs at since it's DDR (Double Data Rate). So a 1600MHz stick would be running at 800MHz in reality.

[harrynowl]

It's the frequency in millions of transfers per second 

 

The clock rate is half the listed speed (so 1600 ram clocks in at 800mhz), because it is double data rate.

[Godlygamer23]

It has to do with the clock speeds that the RAM is guaranteed to run at, given a proper memory controller. The speeds advertised are double the actual clock speed due to the DDR technology - DDR stands for Double Data Rate. The number is the effective speed, commonly determined "mega-transfers" instead of megahertz(unit is stylized as MT/s vs MHz).