31 Aug
2006
31 Aug
'06
3:34 a.m.
Am 30 Aug 2006 18:58 meinte Jay West:
Sean wrote....
> I seem to recall a supercomputer made by Intel that used Pentiums. I
> forget the name though, but it was quite a behemoth of a machine from what
> little I recall (many CPUs).
Wasn't that "The Connection Machine"?
Nop, for one it was way before the Pentium, second it wasn't
realy big at all. The First one was based on a custom CPUs -
often you'll find a reference that this have been 6502s, but
that's not true. Most of the computation was done by the 65k
of 1 Bit CPUs, but they where not realy independent. In fact,
it's hard to call tem CPUs at all, since they where barely
more than a specialized ALU wit a function input, two one bit
data and a flag input and a flag and a one bit data output.
But hey, for a marketing purpose 65536 CPUs sounds way better
than just 4k :)
While each had it's own memory (4kx1?), always 16 where feed
by a microcontroller with the same instructions. Form a more
traditional viewpoint such a combination should be called a
single CPU, since it still could only execute one instruction
at a time, but on up 16 data elements simultanious.
It was a bit like an inversion of the 6600 conzept - instead
of having 16 PPs shareing one CPU, it had one CPU with 16 ALUs
The sixteen single bit ALUs where manufactured into one chip.
Only the up to 4096 of microcontrollers where direct addessable
in a 12 dimensional hypercube. The original design was ment to
run AI programms done in LISP, thus FP wasn't realy important.
The CM-2 did fix that problem by changing the structure to
one controller operating 2x16 ALUs and having a Weitek FPU,
so the microcontroller (called Sprint?) was now feeding 32
binary ALUs and one FPU - resulting in the quite common mis-
interpretation that each 32 CPUs did share one Weitek and so
the FPU was still a bottleneck. Also the memory changed (IIRC)
from ALU-seperate to a shared memory for all ALUs.
After the CM-2 came the CM-5 which moved away from the high
performance specific design toward standard SPARC (later
SuperSPARC) with a fat tree, like todays Infiniband.
So, no, no Pentiums inside - the only Intel in here is the
fact, that Weitek was founded an run by former Intel people.
Gruss
H.
--
VCF Europa 8.0 am 28/29.April 2007 in Muenchen
http://www.vcfe.org/