SMD controllers on 4D/240

[Rayan Zachariassen]

markb at denali.sgi.com (Mark Bradley) writes:

>As for buying and integrating your own, I don't recommend it, as you may or
>may not get the right rev. levels of f/w, h/w or whatever.  And cable impedance
>is critical for these disk drives, as is the right grounding scheme, etc.

It really isn't that bad... it is hard to go wrong in hooking up an SMD
drive (although when you get 220V out of 110V sockets...).  The more serious
problem is getting disks that work with your controller that work with your
vendor-supplied or home-grown driver.  We are not enamored by the default
controller on SGIs, nor the preferred disks, and this combination is indeed
sensitive to rev. levels just now being fielded.  I would recommend using
SGI's supported configuration (from SGI if you value your grey hairs, I gather)
unless you have very specific needs or experiences that make you feel
it is worth the hassle of listening to SGI people saying "told ya'".

I do know for a fact it is possible to do everything homegrown, both an
SGI-subsystem-clone configuration [which is what you're probably interested in]
and a specific controller/disk combo we like to use around here on heavy
timesharing Sun configurations (Ciprico Rimfire/Fujis).

>I recently also heard that one of our customers mistakenly plugged a drive
>into the wrong voltage (easy to do) and blew up the power supply for the
>drive.

>But, that's my opinion (and in this case, maybe that of my employer...)

I hope so (or if its SGI speaking, hope not).  Our machine was inches from
the machine referred to here, and the mildest retort to that statement would
label it "revisionist history".  The victims may comment themselves.

However, after the event we were all wondering what the point of having
fool-proof socketing standards -- incompatible sockets for different voltages
-- is, if they aren't applied (no, the customer didn't supply the metaphoric
fool).

ps: frankly, at this point, all SMD subsystems are bad relative to the speed
of the rest of the system, its just that some are worse than others for
various kinds of activities.  If we can afford IPI subsystems or some other
faster I/O technology, we'll be buying that for our machines asap when the
money can be found.

rayan