AMD 7770 question

[feofhweufheuiwhfef]

I am looking to get an AMD 7770.

According to litecoin.info, these are the types of 7770s tested.....

https://i.imgur.com/BsfXOmp.png

first column is Mhs, 2nd is core clock, 3rd is memory clock...

But when I look for this item on websites like scan.co.uk, I get the following

https://i.imgur.com/mscNiTP.png

As you can see, memory clock is 4500 Mhz.....

I don't get it.... Why is memory clock 4500 Mhz...?? All the ones on litecoin.info show between 1125 and 1425 memory clock... 4500 Mhz is vastly more..??

What is going on here..

[DarthMuffin]

That's the "effective memory clock".  It's a marketing gimmick.  The actual clock is less but but it's a wide pathway.  I don't know the exact specs on that card but probably something like a 32-bit processor and a 128-bit wide memory bus so 4x the bits are pushed through on each clock cycle.