[comp.unix.wizards] Emulex SC41 disc controller

ejd@goanna.oz (Erick Delios) (08/30/88)

After suffering yet another head crash on our RA80/RA81 disc drives it
has been decided to throw the UDA disc controller and RA series drives 
out.

We are looking at replacing the UDA with an SC41 controller. I can find
no explicit mention that this controller works with under 4.3.

Will this controller work on a Vax 11/750 ?
If so will it work as well as a UDA  ?

Thanks,

Erick Delios				 UUCP:	    uunet!munnari!goanna.oz!ejd
					 INTERNET:  ejd@goana.oz.au
					 ARPA:      ejd%goanna.oz@uunet.uu.net

ejd@goanna.oz (Erick Delios) (08/30/88)

After suffering yet another head crash on our RA80/RA81 disc drives it
has been decided to throw the UDA disc controller and RA series drives 
out.

We are looking at replacing the UDA with an SC41 controller. I can find 
no explicit mention that this controller works under 4.3.

Will this controller work on a Vax 11/750 with BSD 4.3 ?
If so will it work as well as a UDA  ?


Thanks,

Erick Delios				 UUCP:	    uunet!munnari!goanna.oz!ejd
					 INTERNET:  ejd@goana.oz.au
					 ARPA:      ejd%goanna.oz@uunet.uu.net

chris@mimsy.UUCP (Chris Torek) (09/01/88)

In article <1508@goanna.oz> ejd@goanna.oz (Erick Delios) writes:
>We are looking at replacing [a UDA50+RAxx] with an SC41 controller.
>I can find no explicit mention that this controller works with under 4.3.
>
>Will this controller work on a Vax 11/750 ?
>If so will it work as well as a UDA  ?

We have one on a VAX 8250 running 4.3BSD-tahoe.  In a previous
incarnation it was a VAX-11/750.  Yes, it works; but maybe not with the
stock 4.3BSD driver.  (The 4.3BSD-tahoe driver is fine, obviously.)
There is also a bug in early firmware revisions on the SC41/MS that
causes it to hang a 750 such that only the little white `RESET' button,
or power cycling, unhangs it.  This bug shows only under heavy loads;
Emulex would not believe it existed until VMS V4.4 was sped up enough
that it showed there.

We have three CDC9771s on the controller.  Their maximum throughput
(from `dd if=/dev/rra?c of=/dev/null bs=63k') is lower than that of a
UDA50/RA81 (~600KB/s vs ~780KB/s) but their average transfer rates are
about equal.

Emulex support for the SC41/MS on the VAX 8250 is dismal.  In
particular, the EVM.EXE we have runs only on 750s, 780s, and uVAX-Is,
so the formatter cannot be used.  Emulex have told us that they will
not do anything for us unless we buy their new controller, the UD33;
they have not been very specific about what they will do if we do.
(One of these days I have to finish reverse engineering the monitor
and formatter, preferably *before* one of the CDCs dies.)

The UD33 has a whole 51 or 52 sectors of buffering, as opposed to
something like 10 or 20 on the SC41/MS.  (When will drive manufacturers
learn that an on board cache should mean numbers in *megabytes*, not
mere tends of kilobytes?)  It probably also handles XMD drives; the
SC41/MS will only do SMD.  Given the prospect of better support and
the ability to use newer (XMD) drives, the UD33 is probably a better
bet.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@mimsy.umd.edu	Path:	uunet!mimsy!chris

muller@sdcc7.ucsd.EDU (Keith Muller) (09/01/88)

In article <1510@goanna.oz>, ejd@goanna.oz (Erick Delios) writes:
> ...... 
> We are looking at replacing the UDA with an SC41 controller. I can find 
> no explicit mention that this controller works under 4.3.
> 
> Will this controller work on a Vax 11/750 with BSD 4.3 ?
> If so will it work as well as a UDA  ?

I use emulex sc7003 disk controllers on a 750. They are directly supported
by 4.3BSD (and 4.3BSD-tahoe) and are CMI boards not unibus (they look like
a massbus to the software). I have never had a single problem with them or
the older SC750's they replaced.

	Keith Muller
	UC San Diego
	muller@ucsd.edu

grr@cbmvax.UUCP (George Robbins) (09/01/88)

In article <1082@sdcc7.ucsd.EDU> muller@sdcc7.ucsd.EDU (Keith Muller) writes:
> In article <1510@goanna.oz>, ejd@goanna.oz (Erick Delios) writes:
> > ...... 
> > We are looking at replacing the UDA with an SC41 controller. I can find 
> > no explicit mention that this controller works under 4.3.
> > Will this controller work on a Vax 11/750 with BSD 4.3 ?
> > If so will it work as well as a UDA  ?
> 
> I use emulex sc7003 disk controllers on a 750. They are directly supported
> by 4.3BSD (and 4.3BSD-tahoe) and are CMI boards not unibus (they look like
> a massbus to the software). I have never had a single problem with them or
> the older SC750's they replaced.

For sure - No earthly reason to use an Emulex unibus controller in a
750 unless you maybe happen to have one lying around.  There's a SC750
somewhere in the guts our olde 750 and other than the drive cable
paddleboard falling off cause somebody lost the bracket, it's been
running since the machine was born - ~5 years, ~3 sites ago...

SC750/7000 = 1.8 MByte/sec - Eagle Class, SC7002 = 2.5 MByte/sec - just
about anything - SC7003 3.0 MByte/sec XMD-III and other scorchers...

-- 
George Robbins - now working for,	uucp: {uunet|ihnp4|rutgers}!cbmvax!grr
but no way officially representing	arpa: cbmvax!grr@uunet.uu.net
Commodore, Engineering Department	fone: 215-431-9255 (only by moonlite)