Wide ULTRA 3 SCSI 18.2 gb How Much?????

[leirbag28]

I have 4 18.2gb 10,000rpm harddrives:

three COMPAQ Model  BD018635C4
18.2gb 10,000 rpm Wide Ultra 3 SCSI

and one HP Model BD01865CC4
18.2gb 10,000rpm Wide Ultra 3 SCSI

comes with an adaptor card to connect all 4 HD's together.


How much should I ask for this entire package?  and is anyone interested in these for maybe their TOASTER or FLYER

They seem like they are pretty darn fast!  10,000 RPM.


Im in Queens New York

[Matt_H]

I paid $36 for an 18GB SCSI drive about 3 years ago, if that's any indication to go by.

[orange]

hm, those UW SCSI drives, can they be connected to any standard 50 pin Amiga controller with adapter? How many pins do UW drives have? Can an ordinary passive adapter do the job?

[leirbag28]

I have no idea how it connects to the Amiga....I have seen SCSI on the Amiga.and that just looks like a longer IDE connection.......but these are different.i know there is an adaptor.and I believe these are able to connect to the Amiga.

but for th Most part I dont know much about SCSI on the Amiga........but it looks like these hard drives are quite fast!  as fast as Some current SATA drives

[djbase]

UW-SCSI has 68 pins, U-SCSI has 50 pins. So a 68->50 pin adapter will work.

[magnetic]

We currently have many nice Uwscsi adaptors for sale on ebay that work great for amiga:

http://search.ebay.com/_W0QQsassZeastcoaster212QQhtZ-1

magnetic

Also some other rare/cool items

[leirbag28]

BUMP

[stopthegop]

They're probably server drives.  If thats the case, most likely these have an "SCA" type connector which is 80 pin (male on devices, I think).  Anyway, yes these will work with any Amiga scsi controller, but with a couple of catches.  First you need an SCA adapter to transform the drive into whatever type of scsi connector your internal passthrough cable and your Amiga controller have.  No Amiga controllers (that I am aware of) have 80 pin SCA connectors.   For example, you'd need an SCA(f)->68pin(f) if using the controller on a Cyberstorm MKIII.  In this instance, you would also need a passthrough cable equal to the TOTAL number of drives you plan to connect PLUS THREE.  Four drives -> 7 position cable.  Next, the SCA adapters usually have terminating resistors installed by default.  These must be removed before using them in an Amiga.  Finally, be aware that the speed of these drives means nothing if you don't hook them up to a SCSI II or III controller which is specified as "WIDE" (16 bits per word vs. 8 bits per word - or "narrow").   Any scsi controller can talk to these drives; the problem is the entire bus will automatically synchronize down to the speed of the slowest device on the bus.  If the controller itself is the slowest device, then guess what??  Everything goes that speed.  With scsi, its "follow the slow-poke".     My advice is this:  yes, by all means hook them up to an Amiga.  But only if you have a SCSI II or III controller such as the Commodore 4091 or the onboard controller on Cyberstorm cards.  And definately do not connect crap like scanners, cdr, or zip drives to this bus!  One slow device on the chain will just kill your throughput.  Best of luck.      

[Piru]

@stopthegop

Any scsi controller can talk to these drives; the problem is the entire bus will automatically synchronize down to the speed of the slowest device on the bus. If the controller itself is the slowest device, then guess what?? Everything goes that speed. With scsi, its "follow the slow-poke".

This is nonsense. SCSI does not slow down to the speed of the slowest device in the bus.

The SCSI controller naturally sets limit to maximum possible speed, however. You can't go faster than the controller maximum speed.

[Framiga]

I have heard those thing a bunch of times but, personally i don't see any slow down using:

A SCA 80 pin 10000rpm
and a UW 68 pins 7200rpm.

They go at theyr "maximum" speed (the SCA if faster as aspected...~36MB/s versus the less than 30MB/s of the other)

NOTE- this on CSPPC UWSCSI controller... no idea about the BPPC one.

isn't those thing IDE related?

[stopthegop]

You're mistaken.  If you have a "Narrow" (8 data bits per cycle) device on a bus with "Wide" (16 bits per cycle) devices and "Wide" controller(s), then the overall width of the data path is 8 bits.  How are you going to cram 16 bits through only 8 wires in a single clock cycle?  The answer is you can't.  You can do it in two clock cycles, but not one.  That effectively cuts your overall performance in half, which is what I said earlier.  I know this is true.  I work for a manufacturer of SCSI periphreals.  I've done tests myself in the lab and in the field.  Granted, there is one way to "cheat" that I know of; that is to get decent performance on a Wide bus even with a Single-Ended device attached.  In order to work, the "slow" device must not reside physically between the "target" and "initiator" hosts, both of which are presumably Wide.  Second, it won't work with active termination.  If these two conditions are met, then yes. it is possible to get 'close' to rated throughput.  This is more true with a short bus length using LVD (Low Voltage Diff) devices. This is a dirty solution, imo.  And it won't work on the Amiga/Cstorm controller anyway because it requires active termination.

[leirbag28]

Well Thats All folks!  I sold it all yesterday for a Measly $20

and Included a PCI SCSI 3 contoller with an extra SCSI 2 9gb 7200RPM HD   and also added a 450 Watt Pentium 4 PSU for $15.


I know I got ripped off, but I needed the cash right at the moment.

I was hoping some Amiga dude would buy it as is far more worth to an Amiga user.

[Framiga]

ugh! better don't say how much i've paid mine! :-( anyway good for the buyer

@stopthegop

"You're mistaken. If you have a "Narrow" (8 data bits per cycle) device on a bus with "Wide" (16 bits per cycle) devices and "Wide" controller(s), then the overall width of the data path is 8 bits. "

yes under such situation your right but we weren't speaking about 8 bits Narrow devices and AFAIK, (if mixed) they requires a particulat termination (are seen as 2 different chain)

Edit- and the SCA (as you know) are forced in SE under Amiga controllers

[Floid]

leirbag28 wrote:


Well Thats All folks!  I sold it all yesterday for a Measly $20

and Included a PCI SCSI 3 contoller with an extra SCSI 2 9gb 7200RPM HD   and also added a 450 Watt Pentium 4 PSU for $15.


I know I got ripped off, but I needed the cash right at the moment.

Don't feel too bad.  You can get 200GB 7200RPM ATA or SATA drives these days for only twice that, which, 'sadly' enough, will likely trounce those simply for platter densities and large caches.  With NCQ on recent SATA hardware, or software patches that simulate it (NetBSD has, for example), you can get close to one of SCSI's other major advantages.

I love SCSI myself, but after comparing throughput, I'll take a 100+GB drive over previous generation hardware in almost all cases.

...

Now, when it comes to popping wide devices on narrow chains,  to be absolutely assured of compatible cabling, it pays to use 50<->68 adapters which include "high-byte termination."  'Many' drives will function without it, but I had the luck to land some 4GB IBMs back in the day with no onboard termination whatsoever, and same decidedly couldn't cope with having half their bus floating.  Got the wide side of the bus appropriately terminated, and bam, instantly recognized and working.

If you want to use narrow devices on wide chains, technically one's supposed to opt for 68<->50 pin adapters (unterminated, naturally) along the bus rather than placing two terminators at separate physical offsets.  In practice, you can often just use something like a 2940UW which is built to cope with however they designed the two 'halves' to the bus.  (I was once told that these designs are slightly more technical cheats -- more of an on-chip bridge versus a straight-through bus -- than just applying switchable termination, but I've never looked at an AIC chip pinout to find out if that's really the case.)

...

Kudos to all the real gurus who've finally settled what really happens with a slow device on a fast bus.