Re: max zip speed?

[irsman@winternet.com (Ian Schmidt)]

In article <4n5lbu$acv@asia.lm.com>,
Matt Portune <mportune@telerama.lm.com> wrote:
>Assuming I have an '816 that can do 20MHz, can the rest of the zip do 
>20MHz?  I mean, what does the card max out as?  What about SRAM?  Would 
>15ns be fast enough?  Thanks!

I've heard varying stories on this...evidentally the ASIC can do 20 mhz,
barely, but there may be other trouble.  Note that speeds above 12 Mhz offer
very quickly diminishing returns due to the fact that the GS's main RAM is
still 2.6 Mhz and I/O is still 1 Mhz.  Assuming you pulled off 20 Mhz, that
would put the CPU at around 8 times as fast as RAM and 20 times as fast as
I/O, at which point something has to give and the CPU will just spend most
of it's time waiting on cache misses.

--
Ian Schmidt - irsman@winternet.com - http://www.winternet.com/~irsman/
    "Where would I be without IBM?" - P. Robb, Information Society