[rescue] SS10 HD bracket - now what is...

[James Lockwood]

On Tue, 28 May 2002, Michael A. Turner wrote:

> 	Thanks that helps a lot. I found a picture on memoryX's site and I
> agree they look easy to make.

I use screws and small rubber grommets, but the idea is identical.  The
inner surface of the Sparc 10 case is coated with copper paint, make sure
that the drives do not contact this.

> 	Now my curiosity turns to the mini dimm slots next to the main dimm
> slots. are these for this item? "2mb NVRAM Simm for Sparc 10/20 (501-2001)"
> What are the merits to having these in place? I have none currently, is that
> bad? Do they go in as singles or in pairs?

The SS10 can take two NVRAM SIMMs of 2MB each.  These are battery-backed
SRAM used for disk write caching.  They provided significant speed
improvement in the days of NFSv2 which required frequent synchronous disk
metadata updates.  NFSv3 mitigates much of this problem, but they still
offer speed acceleration if you are going to have heavy disk access
involving file creation and deletion.

They are rare.  I looked for a couple for years with no luck, and then ten
of them landed in my lap at once.  MemoryX may have them in stock.

They occupy both the small "outboard" slots next to the main memory slots
as well as the corresponding main memory slots (they look like extra-long
DIMMs) and therefore lower the maximum amount of memory you can stuff into
the machine.  You need the Solaris PrestoServe software to enable them, I
have a copy floating around if anyone happens to need it.

The Sparc 20 and 10/SX can also use 4MB or 8MB VSIMMs (video SIMMs) in the
same slots, which are totally different.  These provide onboard 24-bit
video and have nothing to do with disk acceleration.

-James