1 Gigabyte SCSI Disks: Comparison Table
Charlie Byrne
Comments please. Fill in what you can.
What else should be on here? What "transfer rate" is important?
Most prices are from exhaustive search of July 1993 Computer Shopper.
Warranties are manufacturers. All are half height. I believe all are SCSI-2.
Major Vendor 1 Gb SCSI Disks Comparison Table
===========================================================================
Capacity Avg Buffer Transfer Best Wrnty
Vendor Model (mb) Seek RPM Size kb Rate mb/s Price Yrs
========== ======== ======== ==== ==== ======= ========= ===== ====
Seagate 12000N 1050 10.5 999 5
Micropolis MC2112S 1050 10.0 5400 512 1029 5
Quantum PRO1050S 1050 10.0 4500 512 1049 2
DEC DSP1050 1050 9.5 5400 512 1158 5
DEC RZ-26 1050 9.5 5400 512 1670
Fujitsu FJ2694S 1080 10.0 5400 512 1029 5
Toshiba MK538-FB 1200 12.0 3600 512 1045 3
Maxtor MXT1240S 1240 8.5 6300 1219 1
===========================================================================
Charlie Byrne * University of Miami * Div of Marine Biology and Fisheries
4600 Rickenbacker Causeway, Miami, FL 33149 * Voice: (305) 361-4705
Usual disclamers apply.
Charlie Byrne
by...@rcf.rsmas.miami.edu (Charlie Byrne) writes:
>I want fast 1 GB disks for my Alpha.
Does anyone make SCSI disks with RPM > 5600?
Eugene Chu
Seagate's 12550 (or something like that) called the Barracuda series
are 3.5 inch half height, 2GB formatted capacity drives that revs at
7200 rpm. Transfer rates are from 4.5-7 MB/sec I think. They are available
with fast SCSI-2 single/differential narrow/fast interfaces. I think street
prices for these things are around $2000 each. I'm sure the other competing
companies will be quick to release similar drives in the near future.
eyc
--
>:< Me: Eugene Chu (Mr. Butterfly) | Radar Science & Engineering >:<
>:< c...@hanauma.jpl.nasa.gov | Jet Propulsion Laboratory >:<
"T'is better to light a single candle than to curse the darkness"
But t'is so much easier to curse the darkness.
Paul Nankervis
Yes the Seagate Barracuda spins at 7200 RPM. This 3.5" drive comes with
either 1.4 or 2.1 Gbytes and because of the 7200 RPM has an average
rotational latency of only 4.17msec. It has an average read seek time of
8.0msec, comes with 1Mb cache, and has interfaces for fast and fast wide
SCSI-2. It has features like read-ahead, write-merging, command-queuing, ...
One interesting option on this drive is the ability for 'Write Immediate'.
This option returns command complete to the host as soon as the write data
is transferred into the drive's buffer. The drive can then do the real
write afterwards - too bad if the power goes off in the meantime!
We were thinking of getting a few of these drives for an alpha system but
were put off because of the heat load they generate! We are getting RZ28s
instead but may still try out a Barracuda down the track! (If anyone is
already using one I would love to know!)
Paul Nankervis ,-_|\ Email: P.Nan...@latrobe.edu.au
Computing Services / \ Tel: +61 3 479 1889
La Trobe University \_,-\_/ Fax: +61 3 479 1999
Bundoora, 3083 v
AUSTRALIA
Charlie Byrne
>Seagate's 12550 (or something like that) called the Barracuda series
>are 3.5 inch half height, 2GB formatted capacity drives that revs at
>7200 rpm. Transfer rates are from 4.5-7 MB/sec I think. They are available
>with fast SCSI-2 single/differential narrow/fast interfaces. I think street
>prices for these things are around $2000 each. I'm sure the other competing
>companies will be quick to release similar drives in the near future.
Barracuda 1 is Seagate ST11750N (Fast SCSI-2) or ST11751N (Fast Wide SCSI-2).
Add a "D" to model number for differential.
Formatted Capacity = 1.4GB
1 MB Cache
Internal Xfer rate = 4.5 to 7 MB/s, External = 10 to 20 MB/s
Track to track seek = .6ms read / .9ms write
Avg seek = 8r/9w
Max ssek = 19r/20w
Avg latency = 4.17 ms
Barracuda 2 is Seagate ST12550N (Fast SCSI-2) or ST12551N (Fast Wide SCSI-2).
All same as Barracuda 1 except
Formatted Capacity = 2.1GB
Charlie Byrne
SCSI
SCSI-2
SCSI Fast
SCSI Wide
SCSI Differential
Thanks.
Martin Lurie
last issue, Sept. of Byte Mag I believe did a review on
large HD and it Should still be in the book store.
Micropolis Microdisk 2GB 5400 rpm, Data transfer kb 3445
per second, seek 15 Latency 6 = Access time 21 Take
care, Marty
In article <27pllk$c...@umigw.miami.edu>, Charlie Byrne
(by...@rcf.rsmas.miami.edu) writes: >In article
--
Martin B. Lurie internet:ma...@mauihawaii.win.net
214 Mahie Pl. cis userID: 76350,2142
Kihei HI 96753-9449
808-879-6855 "A friend of Bill W."
Eugene Chu
Charlie Byrne <by...@rcf.rsmas.miami.edu> wrote:
>OBTW can some kind soul enlighten me on differences of:
SCSI
- original spec adopted by ANSI, a modification of Shugart Associates
System interconnect (SASI). Provided communication functions among
small computer devices. A lot of device manufacturers built products
that were "SCSI compatible", but each had its own interpretations of
the specs, leading to a lot of incompatible devices.
SCSI-2
- A new ANSI spec which hoped to unify all the SCSI implentations
and tighten the old specifications. Also added new features such
as synchronous transfer mode (5 MB/sec), fast transfer mode (10 MB/s)
wide data path (16 bits instead of 8, implying 20 MB/s max data rate)
and double wide data path (32 bits, 40 MB/s). New functions for
device to device transfers, multi-initiator (hosts), bus release,
etc. were also added.
SCSI Fast
SCSI Wide
SCSI Differential
- Normal SCSI cables run "open ended"; each signal has only a
ground wire to reference to. This was fine for narrow slow
transfers over cables less than 20 feet, but in fast modes (or
longer cables), were susceptible to noise. The differential mode
uses pairs of wire carrying signal represented by voltage
differences between the pair, and is more immune to noise, and
the spec allows 80 feet of cables between the farthest two
devices. (You'll be amazed at how quickly 20 feet is used up
in a typical rack set up, especially when the disks are dual-
ported between two VAXs.)
>Thanks.
>Charlie Byrne * University of Miami * Div of Marine Biology and Fisheries
eyc
Charlie Byrne
Includes SCSI and IDE drives from 250 - 2000 MB.
Seagate ST12550N "Barracuda" is apparently the fastest SCSI drive known to man.
The "Best" picks were:
250-350 MB Seagate ST3390A
400-600 MB Maxtor MXT-540SL
1-2 GB Seagate ST12550N