larryd1@killer.Dallas.TX.US (Larry Clark) (03/31/89)
My employeer has need of large, high reliable disk drives with high
data transfer drives. The micropopolis esdi drives meet the data
transfer rates nicely, but their mtbf falls short by some 10,000 hours.
Can anyone recommend a manufactorer who makes drives that have a
capacity of 150 megs or greater and a MTBF of 50,000 hours? Price is
not a factor, but data transfer rate is, so I suspect that ST506 is
out and esdi or scsi is in.
Thanks
Larry D. Clarkpalowoda@megatest.UUCP (Bob Palowoda) (04/01/89)
From article <7715@killer.Dallas.TX.US>, by larryd1@killer.Dallas.TX.US (Larry Clark): > > My employeer has need of large, high reliable disk drives with high > data transfer drives. The micropopolis esdi drives meet the data > transfer rates nicely, but their mtbf falls short by some 10,000 hours. > > Can anyone recommend a manufactorer who makes drives that have a > capacity of 150 megs or greater and a MTBF of 50,000 hours? Price is > not a factor, but data transfer rate is, so I suspect that ST506 is > out and esdi or scsi is in. > > Thanks > Larry D. Clark I beleive Core International and Prime have 50,000 mtbf. Actually Prime has a 5 year warrenty of some sort which works out to be 43,000 mtbf. I once worked in a QA department that derived these figures from one year data. What I would be interested in is what bearing manufacture is used for what drive. On the subject of disk transfer rates I have been reading some interesting results of these benchmarks in MIPS magazine. The one that caught my attention is the Rupp 386 machine using a ESDI controller with cache for the controller. Other ESDI setups transfered 100k/bytes/sec (1meg/1task) and the Rupp controller did over 400k/bytes/sec(1meg/1task). Rupp Computer products advertise this disk controller as "PM3011 Caching Controller". List for 1150.00. Does anyone know who manufactures this controller? Another question is how do different ESDI device drivers affect the disk tranfer rate. And why or how did the caching controller override this limitation? ---Bob -- Bob Palowoda Work: {sun,decwrl,pyramid}!megatest!palowoda Home: {sun}ys2!fiver!palowoda BBS: (415)796-3686 2400/1200 Voice:(415)745-7749
jbayer@ispi.UUCP (Jonathan Bayer) (04/01/89)
In article <7715@killer.Dallas.TX.US> larryd1@killer.Dallas.TX.US (Larry Clark) writes: > > My employeer has need of large, high reliable disk drives with high > data transfer drives. The micropopolis esdi drives meet the data > transfer rates nicely, but their mtbf falls short by some 10,000 hours. > > Can anyone recommend a manufactorer who makes drives that have a > capacity of 150 megs or greater and a MTBF of 50,000 hours? Price is Priam offers drives with a 3 year guantantee. A company called Phoenician Faire is selling 330 meg priams for $ 1625. I have no connection with Phoenician Faire except as a satisfied customer. JB -- Jonathan Bayer Beware: The light at the end of the Intelligent Software Products, Inc. tunnel may be an oncoming dragon 19 Virginia Ave. ...uunet!ispi!jbayer Rockville Centre, NY 11570 (516) 766-2867 jbayer@ispi.UUCP
Chip_N_Oliver@cup.portal.com (04/02/89)
In article <7715@killer.dallas.TX.US> larryd1@killer.dallas.TX.US writes: > My employeer has need of large, high reliable disk drives with high > data transfer drives. The micropopolis esdi drives meet the data > transfer rates nicely, but their mtbf falls short by some 10,000 hours. > Can anyone recommend a manufactorer who makes drives that have a > capacity of 150 megs or greater and a MTBF of 50,000 hours? Price is > not a factor, but data transfer rate is, so I suspect that ST506 is > out and esdi or scsi is in. First of all I think it's crazy to rule out a drive because it's MTBF falls short of some pre-determined requirement by 10k hours. There's a lot of factors more important than MTBF that will determine when and whether a drive will fail (and luck may even take a large part). Second, for the bulk of applications, seek time is much more important than transfer rate. I'd rather have an 18ms ST-506 drive over a 40ms ESDI drive anyday. Chip Oliver coliver@cup.portal.com Lockheed Missiles and Space sun!portal!cup.portal.com!coliver
dlu@wobble.UUCP (Doug Urner) (04/04/89)
In article <3239@megatest.UUCP> palowoda@megatest.UUCP (Bob Palowoda) writes: >From article <7715@killer.Dallas.TX.US>, by larryd1@killer.Dallas.TX.US (Larry Clark): >> >> My employeer has need of large, high reliable disk drives with high >> data transfer drives. The micropopolis esdi drives meet the data >> transfer rates nicely, but their mtbf falls short by some 10,000 hours. >> >> Can anyone recommend a manufactorer who makes drives that have a >> capacity of 150 megs or greater and a MTBF of 50,000 hours? Price is >> not a factor, but data transfer rate is, so I suspect that ST506 is >> out and esdi or scsi is in. According to the distributor that we are using CDC either just upped the MTBF rating of their Wren drives to 50,000 hours, or is about to. Currently they are rated at 40,000 hours with a 5 year service life (whatever that is). > On the subject of disk transfer rates I have been reading some interesting > results of these benchmarks in MIPS magazine. The one that caught my > attention is the Rupp 386 machine using a ESDI controller with cache for > the controller. Other ESDI setups transfered 100k/bytes/sec (1meg/1task) > and the Rupp controller did over 400k/bytes/sec(1meg/1task). > Rupp Computer products advertise this disk controller as "PM3011 Caching > Controller". List for 1150.00. Does anyone know who manufactures this > controller? The PM3011 is made by DPT (Distributed Processing Technology) in Maitland, FL, 305/830-5522 (might be area 407 my Rolodex and the company propaganda differ, I'm inclined to trust the Rolo since I used it to get the propaganda). The controller comes in ST506, RLL and ESDI versions. The ESDI version (at least) supports up to four drives. The controller emulates a WD1003 so it supposedly will co-exist with any OS that will run on a "standard" AT. > Another question is how do different ESDI device drivers affect the > disk tranfer rate. Some factors in how a driver will influence disk throughput are the interleave that the driver supports and how efficently the driver manages the disk arm. The early 386/ix drivers could not support 1:1 interleave and the disk throughput was terrible (and even worse if you set up your fancy 1:1 hardware with a 1:1 interleave...). The later 1.0.6 driver (the "High Performance Disk Driver") did about 500 K per second for transfers up to 250 K where it dropped off to about 40 K per second. The 2.0.1 driver does about the same on small transfers but holds up at around 100 K per second up through 1 MB. I think the fall off on large files is due to running out of buffers (though it is interesting to note that 2.0.1 uses less memory for buffers than 1.0.6). > And why or how did the caching controller override this limitation? The controller can have up to 16 MB of memory. For $1150 you get 512 K of memory on the controller. I would assume that part of what you were seeing was the relatively low access time of the ram on the controller:-). Also if the file system is not too fragmented the cache may be able to have the next block(s) that you read in the controller's memory saving a disk access. -------------------------------------------------------------------------- Doug Urner, Uni-Ops Systems, Bellingham, WA 206/676-5759 dlu@wobble.UUCP