Summary: 3rd party 4-Mb SIMMs

[Patrick Goebel]

A few weeks back I posted a question concerning the possibility of
replacing 1-Mb SIMMs in SPARCstations with 3rd party 4-Mb SIMMs. I
received 12 responses and they were all reassuringly consistent.  Here is
the question (Q:) and a paraphrased summary of the answer (A:).

Q: Judging by recent postings on this board, 4-Mb SIMMs are available and
come relatively cheap (i.e. approx. $500/chip or $125/Mb).  Does this mean
I can simply replace the 1-Mb SIMMs on a SPARCstation 330 CPU board (for
example) with 4-Mb ones?

A: Yes.  People do it all the time.  In fact, it is apparently possible to
mix 'n match 1-Mb and 4-Mb chips on the same board but only in multiples
of four of each type; for example, 4 X 1-Mb + 4 X 4-Mb = 20 Mb total.  One
respondant claimed that one MUST replace all 8 chips at once;  however,
the "multiples of four" rule is apparently verified in practice.

Q: (a) Our Sun sales rep says that Sun's 4-Mb chips will be physically
taller than the 1-Mb version and might therefore only fit on a memory
expansion board and not on the CPU board.  (b) Is this true of all
(reputable) 4-Mb SIMMs on the market?

A: (a) Perhaps the Sun 4-Mb SIMMs are taller (none of the responders was
"dumb enough" to buy SIMMs from Sun) but in any event, there is likely to
be more room on the CPU board for the larger chips than on an expansion
board!  (b) No.  Clearpoint's 4-Mb SIMMs are apparently the same size as
their 1-Mb chips.  The 4-Mb SIMMs from Technology Works are reported to be
slightly larger than their 1-Mb chips but fit is still not a problem.

Q: In addition, our sales rep claims that Sun's 4-Mb SIMM upgrade will
require a PROM swap as well.  Can anyone verify this and elaborate if
true?

A: Replacing the 1-Mb SIMMs on the CPU board with 4-Mb SIMMs requires only
a setting of a clearly marked jumper cable and a reboot.  One responder
also reported having to reprogram the EPROM on a SPARCstation 1 so that
all memory was tested at boot time.  If your machine is loaded with 32-Mb
on the CPU board AND possesses a memory expansion board, a follow on
release of the boot ROM may be necessary.

*** PRICES ***

My estimate of $500 per 4-Mb SIMM was apparently a little wishful.  The
best prices reported were $625/chip from Helios and $725/chip from
Clearpoint.  However, these figures are dropping daily.  If you are on the
verge of ordering a SPARCstation (as we were at the time of my original
posting), it is clear that you will save a bundle by ordering an 8-Mb
version of your machine and swapping out the 1-Mb chips for 3rd party 4-Mb
SIMMs. By the time your machine is delivered, prices may well be below the
$500/chip figure.  The spare 1-Mb chips can be installed on the expansion
board of a SPARC 1 or you can send them to me!

Patrick Goebel--romeo at lindy.stanford.edu