Whats tha difference in between a dual channel memory slot than a regular one ?

Question

why are there some that are dual channel and some that arent ?

Answer 1

dual channel memory are twice the performance of single.

Answer 2

There is no such thing as a "dual channel memory slot".

Dual channel refers to the memory controller on the mainboard being able to talk to two DIMM slots at the same time, rather than just one at a time.  

For maximum compatibility, it's better to make sure that the two DIMMs are exactly the same specs, same latency and everything, even though technically they don't need to be.

So memory makers started making "pairs" of memory by taking them off the line two at a time and packaging them together in pairs and call them 'dual channel memory'. It's mostly a marketing gimmick to charge you more $$$.

In practice, dual channel memory improves overall throughput by about 10-15%. Think about that and the premium you pay over regular memory.  

Answer 3

Dual channel slots are so you can put in 2 of the same size/speed chips in each of the slots. Then what happens is the computer writes to both slots and reads from both slots simultaneously so it in theory doubles the speed.

actually, from the slot perspective they are the same slot, pins etc.