Why dynamic RAM internal frequencies can go any higher

[savage309]

The internal dynamic RAM frequencies are under 250mhz and there obviously is a tech problem to increase that. I wonder what is it - is it that the refreshing talks too long.? Something related with the capacitors ?
For CPU for example, one can easily calculate what power the CPU will generate if the freq gets higher and can see that cooling that won't work. So CPU is power limited.
What hardware problems limits the dynamic RAM ?

p.s. The title is wrong - should be "canT go any higher" ...

 

[SOFTengCOMPelec]

My understanding is that one of the main limitations, is because dynamic rams are using lots of analogue circuitry/amplifiers/comparators, to sense the voltage on the storage capacitors.
Unfortunately, analogue circuitry is inherently speed/bandwidth limited, and tends to be significantly/much slower than digital circuitry.

EDIT
It is mainly the access times, which are limited by the above. Parallelisation techniques, can allow huge data transfers, per access. But there are limits, to how much of that the cpu can usefully use.
Also that fact that the DRAMs are off chip, and using external buses, further limits the maximum data transfer rates.

 

[SOFTengCOMPelec]

Also, I would suggest moving this thread to "Memory and Storage", which is probably where it belongs.

 

[savage309]

Strange, I was pretty sure I am posting in the Memory forum
Thanks a lot for your answer.