14 Nov
2007
14 Nov
'07
6:53 p.m.
On 14 Nov 2007 at 9:48, Eric J Korpela wrote:
Ah, the good old days when processor and memory
operated at nearly the
same speed.
That hasn't been true probably since the 1950's. Core was slow
compared to CPU speeds and drum was even slower, particularly if
random access was employed. Modern memory is actually a closer match
to CPU speed than drum ever was.
That CDC 6600 I described (circa 1964) had 1 usec memory and an
instruction issue rate of 100 nsec. Memory had a 10-way interleave,
so it cost only 100 nsec to fetch successive words. On the STAR-100,
we used 7600 core modules, interleaved and a 512-bit (actually 544
with ECC bytes) memory word size. Memory was slow in 1970 and still
is.
Maybe that's one of those "laws"...?
Cheers,
Chuck