bdm@ciprico.mn.org (Bill D. Moren) (09/18/87)
RIMFIRE 3400 VMEbus HIGH PERFORMANCE ESDI DISK CONTROLLER
Ciprico Inc.'s Rimfire 3400 ESDI controller was developed
to provide UNIX based systems with the highest levels of disk
performance. Advanced data management techniques, a hardware
architecture designed for speed, and extensive UNIX software
support are combined to make the Rimfire 3400 the highest
performance board available.
* 512 Kbyte Lookahead * 30 Mbyte/sec. VMEbus
Cache Buffer Transfer Rates
* Cross-track Lookahead * 20 MHz Disk Serial Rates
Caching
* Extensive Command
* Circular Command Queue Optimization
Software Interface
* Software Support Including
* 48-bit ECC UNIX Drivers
A 512-Kbyte cache memory and high performance micro
processor, coupled with high speed disk and bus interfaces, are
the foundation for improving disk throughput. A large segmented
cache allows multiple tracks of disk data to reside in controller
resident memory, where access times are measured in microseconds,
not milliseconds. The microprocessor's computing power is ap
plied to cache management functions. Additionally, the micro
processor also processes disk requests from the system, using
advanced algorithms that optimize controller and disk operations.
To increase throughput, lookahead caching takes advantage of
the tendency for data files to be stored sequentially on disks.
Disk data subsequent to a specific request are pre-read into the
controller's cache memory. Because files may span track
boundaries, cross-track lookahead pre-reads multiple tracks with
out losing revolutions. Future sequential requests are then
satisfied directly from the cache. This technique, developed
with an understanding of file systems, eliminates costly seek and
rotational delays.
Multiple circular command queues, designed with system soft
ware in mind, link the operating system and the Rimfire 3400
controller. Each queue, with a command capacity exceeding prac
tical limits, receives requests from the operating system driver
asynchronously and without handshake timing restrictions. With
access to all pending disk requests, the Rimfire 3400 controller
will reduce physical latency times by optimizing disk head motion
and minimizing the disk accesses.
With a transfer rate capability of 30 Megabytes/second, the
combination of Ciprico's proprietary Short Burst FIFO gate array
and VMEbus interface maximize system bus utilization. By moving
data across the bus at a rate only limited by the capability of
most memory boards, the Rimfire 3400 controller uses a small
fraction of the available bus bandwidth for data transfers.
Disk drive serial data rates of up to 20 MHz provide VMEbus
system architects with the tools to build a system that has ample
storage capacity at the highest possible data rates. Even if
initial implementations use 10 or 15 MHz drives, upgrading to 20
MHz drives won't require a controller change. Regardless of the
drives selected, intelligent management techniques, such as
automatic overlapped seeks on multiple drives, insure maximum
performance.
Extensive software support, vital to easy integration,
shortens the lengthy start-up process most system integrators are
used to. Support starts with a operating system driver (for
either the System V or BSD 4.2 versions of the UNIX operating
system) developed to take advantage of all the functionality
designed into the Rimfire 3400 controller. Customer support
engineers, experienced with system integration, will provide any
needed assistance during your integration and evaluation. Soft
ware compatibility with the Rimfire 3200 SMD-E disk controller
allows expanding your system's capability by only adding new
hardware to your existing software.
The Rimfire 3400 controller is available today with a list
price of $1995. For more information on the Rimfire 3400
controller, or any of Ciprico's VMEbus, Multibus I, or Multibus
II compatible mass storage controllers, contact Bill Moren at
Ciprico:
Ciprico Inc.
2955 Xenium Lane
Plymouth, MN 55441
(612) 559-2034
or at:
bdm@ciprico.mn.org