Cache board .vs. caching kernel (Re: ESDI controller recommendations)

Vernon Schryver vjs at calcite.UUCP
Wed Sep 6 03:16:36 AEST 1989


UNIX machines much faster than current 386 products can now be purchased from
DEC, Sun, Silicon Graphics, MIPS, Data General, and probably others.  
The first two have machines less than $10,000.  These machines are all at
least 10 times a VAX 780 (i.e. 10VUPS), and so about 2-4 times a fast 386
clone.  For less than $30,000 you can buy a complete 20-VUPS machine.  Less than
$200,000 buys a 160-VUPS multiprocessor with GB of disk.  DEC's run
ULTRIX, which is 4.2BSD based+SV compatible, and therefore of better flavor
than SV.  (Or worse, depending on taste.)  Sun makes much of the similarity
between SunOS4.0 and SVR4.  The remainder have straight or compatible
SVR3.  The file systems on the DEC, Sun, SGI, and MIPS machines are many
times (perhaps 10) as fast as the old 512-byte SV file system.  SGI's
"Extent File System" uses variable size blocks (currently up to 16KB), and
so is possibly much faster than the BSD-FFS on the other 3.  Sun, SGI, and
probably others support "mapped files" which allow applications to
effectively bypass the buffer cache, without giving up the advantages of
kernel buffering.

These prices, for at least three companies, include "real" graphics, rather
than imitations like VGA.  (Before flaming:  VGA is wonderful because it
costs only about $1,000, but it is not in the same universe.)  Ethernet is
also included with most, and at least some run user-TCP >800KByte/sec.

Most of these machines have some low extra cost facility for running DOS
3.x at (they say) AT speed, such as the Ensignia product.

All of these companies have UNIX source, and are not affraid to try to do 
better than AT&T's file system, buffer cache, regions, etc.  Some, including
my day time employer, have been successful.

After buying tape, 2nd hard disk, 2 UNIX's, RAM, TB+, and so on, I have
about $10,000 in this 386 clone.  That may be less than the price of a
useful SPARK Station or DEC 2100 (you need a disk), but not much less.
During the day, I use a <censored>, and find it incomparably faster than
this 386.  Someday maybe I'll be rich and able to replace it.

Anyone buying a machine today should talk to more than the nearest PC VAR.
Sorry, but I don't have useful sales office addresses for more than two of
these vendors, and you should talk to them all, and others such as NEXT.


Vernon Schryver vjs at calcite.uucp   or    ...{pyramid,sgi}!calcite!vjs



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