[SunRescue] Melting SS5?

[Bjrn Ramqvist]

Time for some experimenting. >:-)

Now and then people often wonder if it's generally possible to put a
7200rpm drive into a SS5 (SS4, SS20) without actually cooking that
little pecker.

Last night I had the wonderful opportunity to loan a Fujitsu MAG3091LC
to try a little "experiment".
This drive is a 9GB 10000rpm Wide Ultra-2 SCSI drive with an SCA-2
inderface, and ofcourse is LVD (Low-Voltage Differential, like a
U2W-drives), 2MB cache and with just 5ms access-time!
This one has a 16-pin jumperblock, making up to 8 pairs of jumpers,
controlling (from left to right) ID0-3 (SCSI ID 0-15), WRITE PROT, START
CMD, SINGLE/WIDE and DIFFSENS.

This drive was factory set att Wide & Differential, so I just put two
little jumpers across the last jumper pairs to "degrade" this drive to a
somewhat more pleasent speed the SS5 could handle. :-)
(Thus disabling both Wide and Differential capability)

First of all this is a black and chrome HEAVY beauty, almost 0.7kg,
which is waaay heavier than for example my 500MB Seagate drive which
came original in SS5. :-)
This one actually has some sort of "fins" near the SCA-connector which
probably made me wonder if this was going to dissipate alot of heat.
Anyway, I mounted the drive on a Sun-colored plastic sled and tried
fitting it in the bottom part of the SS5. It sat there nicely and I
tried starting up my 70MHz monster.

At first the drive was rock-silent, as I would expect from the "START
CMD"-jumper disabled. After just a few seconds it started accelerating,
and beeing a 10000rpm drive this is, I would have expect some MAJOR
noise from this one!
Nope.
Infact, when it has spun up to all it's glory, it went almost silent.
Good.
Not that all dead-silent as my Seagate ST34520N (a Conner design)
7200rpm, but very close.

By that time I closed the cover, just to make sure proper airflow and
try listening to the "real" sound enviroment. I put a DEC RRD45 into my
Aurora-2 beauty and tried booting Solaris 2.6 install. (Don't ask me why
I love 2.6 above all other versions)
I filled in all those necessary pieces of information and started a full
install of Sol 2.6. I even ended up having my dinner served and went to
the gym, but hurried back to check out the progress.
As I would have expected, it was finished with the installations, and
was up and running. I tried logging in and carefully listen to the
"funky sound" of that little speedster running in my SS5.
Nice sound. :-)

I shut the whole thing down to console-mode and opened the cover just to
check the temperature of the drive. Remember, this was a single drive,
along with a CDROM sitting there, so it might have been just the
appropriate airflow to hold this one cooled. I touched the drive. Warm.
Every drive gets warm, this one just slightly warmer than all the usual
5400rpm ones.
Ofcourse, you'd all expect that I'd been cooking this speedster, but
nope!
I touched the CPU just for comparisation and couldn't hold my fingers on
it for more than 1-2 seconds.


conclusion:
After all, this worked out just fine. I've never ever seen my slow 70MHz
SS5-monster beeing this rapid and responsive as with this drive, very
probably because of the ultra-low 5ms bad-ass access-time!
And just to assure everyone of you concerning the (almost non-excistent)
heat-problems; get one of those "SS20"-fankits out there, which is
placed right in between the CDROM and the harddrive.
This should certainly keep the drive well under any hazardous
temperatures. But just to make sure, don't put the SPARC trapped in some
sort of under-ventilated box cause that would probably raise
temperature.
I don't see any risk whatsoever in putting a drive like this into your
favourite desktop machine if you keep it with just one drive. This was a
9GB model, but there are 18GB models available also, (hence named
MAG3182LC) so that should be very well enough to put inside a SS5/20.

fact:
"Why on EARTH did you put a 10000rpm drive into this baby anyway???"
I had the opportunity. This drive was labeled COMPAQ, which itself turns
into the fact that I've bought this for my job as an add-on drive.
Compaq REFUSE to sell anything less than 10000rpm drives nowadays, so I
suspect others will follow along that path.
Even now there are a huge need for 7200rpm drives, so all those 5400rpm
would probably disappear.


        /Regards, Bjorn