kaiser@FURILO.DEC (Pete Kaiser, 225-5441, HLO2-1/N10) (01/29/86)
Today Digital Equipment Corporation is announcing three new VAX systems, the VAX
8800, VAX 8300, and VAX 8200 -- the most VAXes, I believe, ever announced at one
time -- and the VAXBI bus. Here's some information about them.
VAX 8800
--------
The VAX 8800 is a two-CPU tightly-coupled multiprocessor -- designed from the
beginning as a multiprocessor -- intended primarily for compute-intensive multi-
streaming applications; in these applications it shows performance in the range
of 2x - 3x that of a VAX 8600. The entire system fits in a cabinet with the
same footprint as the cabinets for the VAX 8600 and the VAX-11/780.
Here's a rough diagram of a VAX 8800 system:
.-----------. .-----------. .-----------.
| C P U | | MEMORY | | C P U |
| # 1 | | 32 MB | | # 2 |
`-----+-----' `-----+-----' `-----+-----'
| | |
| | |
+---------+------ CPU-memory bus -----+---------+
| |
Adapter Adapter
| (optional)
.------+------. .------+------.
| | | |
| | | |
VAXBI VAXBI VAXBI VAXBI
# 1 # 2 # 3 # 4
And here are some technical features:
The VAX 8800 has the full VAX instruction set (but no PDP-11 compati-
bility mode) in both its two tightly-coupled processors. It's built
with custom and semi-custom ECL chips. An integral floating-point
accelerator is standard, and all VAX floating-point data types (F, D, G,
and H) are accelerated. It has 32 MB of memory fully shared between the
two processors over a CPU-memory bus with a usable bandwidth of about
60MB/second. Battery backup for memory is standard.
Each processor has 64KB of cache and a 16Kword (144b/word) writable
control store, of which 1 Kword is user-programmable. The console
device is a MicroPDP-11 with a VT display unit, 1MB of memory, a 30MB
5-1/4 inch disk, RX50 floppy disk drive, and diagnostic port; it
connects to the main CPUs and internal environmental monitoring over a
real-time interface. All modules of the CPU and memory are electrically
keyed, and the console device can read the placement of modules and
microcode levels on each module. Since power-up and power-down are done
through the console device, it won't permit power-up unless everything
is plugged properly in the backplane and has consistent microcode and
ECO levels.
For IO the system has as standard equipment an adapter that attaches two
VAXBI buses to the CPU-memory bus (see below about the VAXBI bus);
another such adapter is optional, and adds two more VAXBI buses. With
the maximum of four VAXBIs, aggregate IO throughput between the VAXBIs
and the CPU-memory bus can reach over 30MB per second. The system
carries as standard IO devices a cluster adapter, an Ethernet port, and
a Unibus adapter.
VAX 8200/8300
-------------
The VAX 8200 and VAX 8300 are systems based on a new single-board VAX CPU which
resides directly on the VAXBI bus. The VAX 8200 has one of these CPUs; the VAX
8300 is a tightly-coupled multiprocessor with two. The VAX 8200/8300 fit in
Digital's H9642 cabinet (22 inches wide by 42 high, similar to a VAX-11/730),
which includes a 12-slot VAXBI backplane and associated power supply, an RX50
floppy disk drive, connector panels, and space for optional battery backup.
There's also a rack-mount version.
The VAX 8200 has approximately the system performance of a VAX-11/780 and the
VAX 8300 has up to 1.9x the performance of a VAX 8200. Like the VAX 8800, the
VAX 8300 is intended primarily for compute-intensive multistreaming applica-
tions. Memory and peripherals are fully shared between CPUs in the VAX 8300.
Here's a rough diagram of a VAX 8200:
.-----------.
.-----------. |
.-----------. | |
.-----------. | |-'
.-----------. | |-'
.-----------. | |-'
.-----------. | |-'
.-----------. .-----------. | |-' | (Up to eight
| C P U | | MEMORY | |-' | | 2MB memory
| # 1 | | 2 MB |-' | | | boards)
`-----+-----' `-----+-----' | | | |
| | | | | | | | |
| | | | | | | | |
+-------+---+------+-+-+-+-+-+-+-+ VAXBI bus
| |
| |
VAXBI
peripherals
And a VAX 8300 system:
.-----------.
.-----------. |
.-----------. | |
.-----------. .-----------. | |-'
| C P U | .-----------. | |-'
| # 2 | .-----------. | |-'
.-----------.-' .-----------. | |-' (Up to seven
| C P U | | MEMORY | |-' | 2MB memory
| # 1 | | 2 MB |-' | | boards)
`-----+-----' `-----+-----' | | |
| | | | | | | | |
| | | | | | | | |
+-+-----+---+------+-+-+-+-+-+-+ VAXBI bus
| |
| |
VAXBI
peripherals
And here are some technical features:
The VAX 8200/8300 CPU has the full VAX instruction set (but no PDP-11
compatibility mode). It's built with eight custom VLSI chips, the
densest custom VLSI CPU design Digital has yet put in a product. An
integral floating-point accelerator for F, D, and G data types is
standard.
A VAX 8200/8300 CPU board has 8KB of single-set, direct-mapped write-
through cache, an asynchronous serial console line, three serial lines
for general use (up to 1200 baud), and an RX50 floppy disk interface.
There is one single position dependency for the boards in a VAX 8200/
8300 system: a CPU board must be in slot 0 of the VAXBI backplane to
provide clocking for the bus. Otherwise any board, including the second
CPU in a VAX 8300 system, may be in any slot. This independence of
position is a characteristic of the VAXBI bus.
The VAX 8200 can be configured with up to eight MS820-AA 2MB memory
boards, the VAX 8300 with up to seven. All memory is fully shared
between processors in a VAX 8300. Each memory module has its own two-
way interleaving controller, providing an aggregate IO write bandwidth
of the VAXBI bus's full capacity, 13.3 MB/sec; and an aggregate IO read
bandwidth of up to 10.0 MB/sec. Battery backup for memory is available.
For IO the system uses VAXBI peripherals. These include the KDB50 disk
adapter, which connects up to four SDI disks (RA81 & RA60); the VAX-
cluster adapter; and the Unibus adapter. See the formal product
literature for details of configuring systems with these peripherals.
Software
--------
The VAX 8800, VAX 8300, and VAX 8200 are available now with VMS, to be followed
by Ultrix.
The VAXBI bus
-------------
The VAXBI, which serves as the IO subsystem of the VAX 8800 and as the backplane
interconnect of the VAX 8200/8300, is designed for true multiprocessing. It is
a clocked synchronous bus with a 200 ns cycle and distributed bus arbitration to
reach 13.3 MB/sec usable aggregate bandwidth (i.e., true bandwidth in actual
use). It is architecturally capable of taking up to 16 "nodes" (options inter-
facing to the VAXBI) in up to 36 modules: i.e., a node can consist of more than
one module. Because of the distributed arbitration within the VAXBI protocol,
the position of options on the VAXBI is immaterial to the bus's operation,
except that the board in slot 0 must provide clocking. The VAXBI has 30-bit
physical addressing, and is fully error-checked end to end. Each VAXBI option
must self-test when power comes on, and is assumed inoperable until proven
operable. The interface to the VAXBI is through a single chip, the BIIC, which
handles the protocol, meaning that the designer of a VAXBI option need not
implement the bus protocol. The fully-specified protocol and interface guaran-
tee that every VAXBI option will operate properly on any VAXBI system.
Literature
----------
VAX Family brochure VAXBI Technical Summary
VAX 8800 System data sheet VAX 8300 System data sheet
VAX 8200 System data sheet VAX 8200 Rackmount data sheet (for OEMs)
VAX Architecture Handbook VAX Hardware Handbook
The bottom two are new (1986) revisions of existing literature.
What follows is a note of possible historical interest.
How many different kinds of VAXes are there? Here's a list of current VAXes
that seem to me to merit being called major variants of the family (deliberately
omitting ruggedized and Tempest VAXes, and variations consisting solely of one
user's change to WCS). This list is, of course, open to debate; in one instance
I've chosen to call something a major variant because of its number. To avoid
any spurious ranking by any possible measure of goodness, the list is arranged
in ASCII sorted order by the names that occurred to me.
MILVAX (note A)
MicroVAX I (D floating)
MicroVAX I (G floating)
MicroVAX II
MicroVAX II multiprocessor (note B)
VAX 8200
VAX 8300
VAX 8600
VAX 8650
VAX 8800
VAX-11/725
VAX-11/730
VAX-11/750
VAX-11/751
VAX-11/780
VAX-11/780 (Purdue variant, note C)
VAX-11/780-5 (note D)
VAX-11/782
VAX-11/785
VAXstation 52x
VAXstation 55x
VAXstation I (D floating)
VAXstation I (G floating)
VAXstation II
VAXstation II/GPX 4-plane (note E)
VAXstation II/GPX 8-plane
VAXstation II/GPX monochrome
Notes
-----
(A) manufactured under license by Norden
(B) no software support from DEC
(C) no support from DEC
(D) not FCC-compliant
(E) color or grayscale
---Pete
Kaiser%BELKER.DEC@decwrl.arpa
{allegra|decvax|ihnp4|ucbvax}!decwrl!dec-rhea!dec-belker!kaiser
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