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Quadra 840 vs. Quadra 650

REGARDING                Quadra 840 vs. Quadra 650
Our project has recently done some experiments comparing the MCL
performance of the Quadra 840AV and the Quadra 650.  So far, we have
been rather disappointed.  The June 1994 article on the PowerMac 6100
shows the 840AV to offer about a third more performance than the 650 on
a broad variety of tasks.  Our experience with a large Lisp application
(minimal I/O, moderate floating point, lots of object creation and
manipulation) shows the two to be about equal.  We were using an 840AV
with 96 megabytes of RAM (60 nanosecond) and a 650 with 40 megabytes of
RAM, though the application was limited to less than 40 megabytes in
both cases, and virtual memory was turned off.

Other results (on the 840AV, but probably similar for the 650?) : we
lost about about 10% of the performance by having extensions enabled
Also, we lost another 20% to EGC.    Finally, there is an extraordinary
hit in performance when we launch the MCL application from a file
server -- in this case, the MCL application can't keep up with normal
type-in.  I would have thought that once the application was launched,
it would be running in local memory, but it feels almost as if it is
paging across the network.

Byron Davies
Motorola Semiconductor CIM, Phoenix, AZ
(602) 897-3502