>>> I therefore see address buses growing at 16 bits every 30 years. That's
>>> just over a bit every 2 years - slower than I expected but not much.
>>> Someone (I forget who) said that memory chips double in capacity every
>>> 18 months. This would give 16 bits in 24 years.
>> Interesting szenario, especialy when connected to the Mores Law
>> (didn't he tell this regarding integration ?).
> Thanks. That's the one I'm thinking of - the amount of memory you get on
> the same area of silicon doubles every 18 months.
Basicly I think its about integrations and transistor
equivalents, but this is just linear to the size of memorys.
In fact, to come back to the original question, Arfon
just took doubling of address space and doubbling of
data bus width for the same thing, but in fact they
are two different functions - widening data bus is
linear, while widening address bus is to the square
(sorry, my mathematical english just stops here).
This means doubble the data bus just doubbles the
date transfer rate (the only thing the data bus is
needed for) or w'=w+w. But doubbling the address bus
is putting the address range (and thats what the
address bus is for) to the square or r'=r*r.
So, while a 256 or 512 bit data bus is usefull (and
already in use in main frames - only called data path),
even a 128 Bit address bus is just nonsense.
Gruss
H.
--
Ich denke, also bin ich, also gut
HRK
Received on Wed Oct 28 1998 - 06:58:18 GMT