SUMMARY: SPARCstation 10 & 20 RAM questions

From: Marc S. Gibian (
Date: Thu May 07 1998 - 15:03:40 CDT

I had asked about issues involved in using RAM from SPARCstation 10 machines in
SPARCstation 20s, since my customer has recently upgraded some 10s and has some
RAM "left-over" from those 10s.

SPARCstation 10 RAM is slower than that needed by 20s. 10s may use 70ns or 80ns
RAM while 20s need 60ns. 10s also only use 16MB or 64MB modules, while 20s may
use 16MB, 32MB, or 64MB modules.

You can not mix anything slower than 60ns in SPARCstation 20s, but its fine to
use a variety of RAM in 10s.

I also asked how one IDs the speed of SIMMs one has onhand. The answers were:

SUN memory Part numbers
machine                 part#   size
SS10                    1785    16
SS10                    1930    64
SS10                    2273    16
SS10/20                 2479    16
SS10/20/U1/2    	2480    64
SS20                    2622    32
You can check and see the printed label on the memory chip to indicate
the speed of the memory. For example, xxxxxxx-60 means 60ns and 
xxxxxxx-70 means 70ns.
The easiest, is to look at the memory chips themselves.  They are always stamped
with the speed.Look for a -6 or a -60 (or -7 or -70)

And I asked if there were any other issues I should keep in mind: --- Please installed the highest memory on the first blank (blank 0), and follow by the rest.

For example, if you have 16mb, 32mb and 64mb. All your 64mb has to be installed on the first few blank and follow by 32mb and then 16mb.

Sun 10s machine can only support 16mb and 64mb memory, while the 20s machine can support 16mb, 32mb and 64mb memory. The 10s can only see the 32mb as 16mb. ---

A few people offered to take any extra SPARCstation 10 RAM off my hands. I'm afraid its owned by the USAF and not mine to offer up. This is rather unfortunate, since a first look through what I have indicates that of the 12 SIMMs currently not in use, only one is 60ns if I go by chip labels, none if I go from the listed Sun part numbers. I will be going though my few remaining SPARCstation 10s to see if any have 60ns RAM, so I can trade the slower RAM I have spare and move any fast RAM I might have into my 20s. But it looks rather bad. I hope I didn't send back any 60ns RAM in the SPARCstation 10s that were traded in for the Ultra-2s.

My thanks to:

Mark Bergman <> "David L. Markowitz" <> Michael Pavlov <> William Teo <> Matthew Stier <> Matt Reynolds <> (Michael Pins)

Marc S. Gibian COMSYS Information Technology Services phone: (781) 377-6350 PRISM/TFS email: or is it: well, maybe: and if all else fails:

attached mail follows:

My customer has had a mix of SPARCstation 10 and SPARCstation 20 workstations,
as well as some new Ultra 1 and Ultra 2 machines. Recently, most of the
SPARCstation 10 systems were upgraded. Only part of the RAM from the 10s had to
be returned as part of the upgrade. SO, I now have a stack of SIMMs that I'd
like to use to expand the memory of the remaining systems. I am most interested
in my 20s, since they currently all have only 64MB while the Ultras all have at
least 128MB.

I believe I remember a SUMMARY that included mention that the speed of RAM for
10s is slower than that for 20s. The SIMMs in my stack have been juggled around,
so I might have some combination of 10 & 20 parts. Thus my questions:

1. Is the speed of RAM for SPARCstation 10s different than that for 20s? If not,
then I can just grab SIMMs and start upgrading my remaining systems, right?

2. How do I determine the speed of the SIMMs I have?

3. Can I mix SIMMs of different speeds? If so, at what cost?

4. Are there other issues I need to consider in performing this upgrade?


Marc S. Gibian
COMSYS Information Technology Services phone: (781) 377-6350
PRISM/TFS email:
                           or is it:
                        well, maybe:
              and if all else fails:

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