Effective memory speed? 4xDrate Nvidia 600 series, AMD 7000 series.

[mikes1992]

hey I was looking at the specs of the new GPUs from nvidia and AMD and realised that there effective memory speeds is 4x the memorys base clocks. Is GDDR5 running quad data rates? I'm really confused, normally the effective rate is just 2x the base clock or as I assumed "DDR, Duel Data Rate".

how do they work out the effective memory clock speeds? Surely if they was running quad data rates they'd bloat about it in the marketing typing "GQDR5!!!!" all over everything lol. Is this because they're running a 4x64bit memory bus? although the 660 is 3x64 and that's still running 1502mhz (6008 effective).


Thanks.

 

[mactronix]

There is a little more to it from a purely technical point of view but Yes in essence they are running Quad pumped memory.
There was a big song and dance about it when it first came out.

Mactronix

 

[mikes1992]

what little information I could find it said that the input clock is doubled (kind of like FSB ratios) and then the output "Effective" clock is doubled due to the Duel Data Rate.

Anybody know where I can find more information on this?

Thanks

 

[mactronix]

Sorry should have included something

http://www.extremetech.com/computing/81778-gddr5-memoryunder-the-hood

Mactronix

 

[mikes1992]

Best answer selected by mikes1992.