Ultra320 SCSI for Macs? Other Server interfaces?

[TylerEss]

I have found that carefully-chosen 10k and 15k SCSI drives are actually quite quiet and cool-running. I've had especially good luck with the Cheetah drives with fluid-dynamic bearings, and some of the later Hitachi UltraStar drives. I had two 72GB UltraStar 10K300 drives in RAID 1 in a quiet workstation... could hardly tell it was on, with the usual mods to reduce drive noise.

Remember that the same bearing and motor upgrades that make desktop drives quiet also make server drives have longer MTBF. Cooler-running is also a reliability improvement. Not all server drives are quiet, but they're not all screamers either.

 

[Trash80toHP_Mini]

I've edited the links to relevant threads I've searched so far into the OP. one more relevant question here.

80 pin -> 50 pin SCSI adapter in SE/30

Do the Ultra 160 and (when voluntarily complient) the Ultra 320 Drives step down into Fast SCSI 2 mode when using these adapters on a Fast SCSI 2 Controller? My working assumption would be that they do, as the spec. for Ultra 3 160 required backward compatibility, but confirmation would be nice!

As always, more links to relevant information and relevant existing threads posted, especially hard won experiences related here are all requested, troops. :approve:

 

[zuiko21]

Those Ultra160/320 drives have to switch down to (Fast) SCSI-2 in order to work with our vintage Macs, for sure...

Besides all Ultra160 (and some Ultra320) drives supporting narrow (8-bit) transfers, some drives need to have that narrow mode enabled or forced via jumpers. IBM's DCHS drives (4.5 GB, 68-pin and SCA versions; quite loud and hot-running ) are among them.

As already mentioned (can't recall the thread, sorry!) I like very much the Seagate-made Compaq/HP BD07285A25 (73 GB, 10Krpm, Ultra-320, SCA; very quiet, moderate power reqs and reasonably cool -- got one of these shoehorned on my LC475!) and they'll work without any jumper tinkering (on the drive) with an adapter like the first one shown in your previous link (the same type I usually use)

On the other hand, got recently a Fujitsu MAN3367MC (36 GB, Ultra-160, SCA; no jumpers) but it refused to work at all with my usual adapters However, a "better" adapter (Siemens branded) with termination resistor packs did the trick, and at 12 EUR it wasn't that expensive either...

In short: those kinds of disks you mention will work down to SCSI-2, but check for jumper settings and/or use a good, terminated adapter -- I presume in order not to leave the unused high byte floating, so the auto switching circuits will be able to work fine.

 

[CJ_Miller]

I am setting up a tower this week with a MDD logic board, and thinking about what to do about drives. It is a server-type tower case and drive access is a pain unless accessed from the front. I could do some kind of PATA or SATA rack or backplane, but it would involve buying stuff I can't afford right now. Can't spend any money.

But I do have an ATTO ExpressPCI UL3D card which I've never used. I have a pile of oldish Compaq (yuck) drives which could work with this. And Compaq backplane and cage assemblies to slot them into. Assuming that the backplane relegates all SCSI handling duties to the controller, I suppose it should work. But, like I said, it's Compaq stuff, so who knows? The power supply is 550 Watts so it should be ok for a few drives.

If it works, it'll probably be noisy. The servers these came out of sounded like VTOL aircraft. Too bad there are so few solid state SCSI drives, I don't understand why, they should work just fine. The ATTO is supposedly supported for Mac OS 9.22 and 10.4, which should have me covered. Also, I've never before tried setting up a Mac to boot from a non-native SCSI bus. Hopefully I can try this tomorrow.

 

[zuiko21]

Some updates on my previous post...

Those HP BD07285A25 drives are indeed great -- head seeks are extremely quiet and quick, draw a moderate amount of power (0.8A @ 12V, although a hefty 1.2A @ 5V) and, if properly formatted, they'll work fine even on '030 machines.

But I have to correct about them running reasonably cool... they can get very hot, but it'll take quite a long time -- and they'll stay warm even several hours after shutoff. Looks like they have some thermal inertia...

Still, I'm afraid that all these SCSI-3 drives, when connected to a "lower" interface via an adapter, go into some sort of crippled mode with much less performance than the host's "narrow" interface would allow, not to say the drive's mechanics!

For instance: I've just installed one of these wonderful HP drives inside my 7600/G3/450, to the internal (Fast-SCSI, 10 MB/s) bus, with a common SCA-50 pin adapter. While everything is working flawlessly and the benefit of a very low access time is clearly perceived, according to HDT Benchmark it peaks at a very pedestrian 3.3 MB/s I was expecting such a 73 GB 10000 rpm drive to top out the interface at 10 MB/s.

On the other hand, the older Quantum Viking 4.5 GB (7200 rpm, native 50-pin) in my dad's 7500 does peak at 8.5 MB/s on the internal bus. If connected to the external port, it goes up right to the interface's theoretical limit (5 MB/s).

Not sure if a "better" (high-byte terminated, etc) adapter would help... I've got one of these for a Fujitsu MAN3367MC (36 GB, Ultra-160, SCA; won't work with regular adapters) and it performed a bit better on the aforementioned machine, peaking at about 3.7 MB/s, but still way below the combo's possibilities...

 

[Bunsen]

Regarding backwards compatibility to older SCSI modes:

It is my impression that this varies from one specific drive model to the next, and that it is important to find and read the manufacturer's support notes to confirm for each drive.

 

[trag]

Regarding backwards compatibility to older SCSI modes:
It is my impression that this varies from one specific drive model to the next, and that it is important to find and read the manufacturer's support notes to confirm for each drive.

Correct. Find the drive datasheet and read it. It's a pain, but like dropping a bomb from orbit, it's the only way to be sure -- without spending money.

For example, I'm currently considering these:

http://www.ebay.com/itm/110917812596?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

http://www.ebay.com/itm/130729532247?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

I found the datasheet here:

http://www.seagate.com/files/staticfiles/support/disc/manuals/enterprise/savvio/10K/100293075d.pdf

And it indicates that SCSI-2 support is built-in.

If I get them, I'll probably use them with this:

http://www.ebay.com/itm/110753860737?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

although I'm tempted to contact the seller and ask him if the termination can be set to only terminate the upper 8 bits. If the only option is to terminate the full bus, then such an adapted drive would need to go at the end of the SCSI cable, and in practice, pretty much mean that you could only use one at a time, or two if you install one internally and one externally.

If someone has found a better/less expensive SCA adapter, I'd like to know. Searching the web in general, the terminated SCA adapters I found were more expensive. I found one or two on Ebay and/or on Amazon which were cheaper and claimed to be terminated, but a close examination of the photographs revealed that there were no components on the circuit board which could be providing termination.

Anyway, I'm not sure there's any point in my buying those to hedge against the future. I have a few IDE/SCSI adapters. And a small stock of IBM 2 GB 50 pin drives (kind of loud, though). But the SCA adapter for these little SCSI drives is cheaper than the IDE/SCSI adapter was even at its cheapest.

 

[TylerEss]

Here are some results from my attempts to connect a Hitachi U320 10K drive to my Mystic:

1) The U320 drive won't work at all with my SCA -> 50pin adaptor. The adaptor works fine with other SCA drives. The U320 drive works fine with a SCA -> 68pin adaptor, both attached to a JackHammer Wide SCSI card and with a 68 -> 50pin adaptor and onboard SCSI.

Any insight on this one is welcome. Both SCA adaptors are the "fully passive" type.

2) The U320 drive isn't bootable in the Mystic. When booted off a 7.1.1 floppy, the drive doesn't even show up in SCSIProbe. It mounts fine (and is smokin' fast!) when the Mystic is booted off another hard drive with System 7.5.5.

I suspect this is because the Mystic has a 53C96 SCSI chip that supports 5MB/s synchronous SCSI, but the ROM driver for it only runs the SCSI bus in asynchronous mode. After booting System 7.5.5, SCSI Manager 4.3 is active and the SCSI bus is run in synchronous mode. I'm remembering correctly that 7.5.5 has SCSI Manager 4.3 for Quadras baked in, right?

Sometime soon I plan to copy the SCSI Manager 4.3 extension onto my 7.1.1 boot floppy. I expect it "should" work in 7.1, since the AV quadras shipped with 7.1 and they have SCSI Manager 4.3 in ROM. If the drive magically shows up after I put the SCSI Manager 4.3 extension on there, then the hypothesis is confirmed.

 

[olePigeon]

I hopped onto FleaBay just to check prices. WOW. $6 + Free shipping for a brand new 36GB 15k RPM Ultra320 drive. Snagged one. Basically free + shipping. This puppy is going into my DP 1Ghz QuickSilver. Zoom!

[Not mine] http://www.ebay.com/itm/Fujitsu-36GB-SCSI-MAS3367NC-15K-U320-Hard-Drive-/170925501321

 

[TylerEss]

I gave up on the 7.1.1 + SCSI Manager 4.3.1 + Sync-only U320 drive test. I'd overwritten my boot floppy with an 8.1 boot floppy and didn't want to re-overwrite it. I put a different 10K drive in the Mystic just to get this project closer to completion.

I can confirm that the SCSI Manager 4.3.1 extension does work with System 7.1.1 on the Mystic! Running Photoshop 3 under 7.1.1 without SCSI Manager 4.3, the efficiency indicator shows sync IO. After installing the SCSI Manager 4.3.1 INIT and rebooting, the little dagger appears next to the scratch efficiency showing that has begun using asynchronous IO calls.

Another interesting result is losing large-block throughput by installing SCSI Manager 4.3.1. I was getting about 6MB/s in the ATTO Performance utility without SCSI Manager 4.3.1. After installing the INIT, the results are hard-capped at 5MB/s. I suspect that this speed decrease is as a result of running the SCSI bus at the 5MB/s synchronous mode when the SCSI Manager 4.3.1 INIT is active.

The Finder is much more responsive during file copies, though -- so overall performance should be higher even though bulk throughput is lower.

 

[Trash80toHP_Mini]

. . . I'll probably use them with this:http://www.ebay.com/itm/110753860737?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

I was just on their page and was wondering if these might be a good choice:

http://www.ebay.com/itm/SCSI-SCA-80-Pin-F-50-Pin-M-Internal-Adapter-/330436901004

Do these seem suitable for my Fast SCSI II Cards a/o for straight up Mac MoBo SCSI?

The higher profile adapters with the 68 pin connector on board tend to get in each other's way when installing pairs inside a case.

 

[TylerEss]

I have one of those adaptors, TRASH. It worked great with an older Ultra2 drive.

I agree about adaptors with both 68 and 50-pin ports on them being bad news. Pick one or the other and stick with it.

 

[Trash80toHP_Mini]

That's GREAT news, I'll have to save up my pennies after making another purchase though! [] ]'>

Luckily, I have a few of the fat kind on the way already, ETA: this week.

 

[olePigeon]

If anyone was wondering, the HDD I bought and linked to above is whisper quiet. I was expecting it to be really loud since it's a 15K RPM hard drive. Nope. It's a good drive assuming I can boot from it. Still working on that part.