Western Digital External HD support

As for booting from a USB drive, I thought that that was impossible - that it has to be Firewire.

Intel Macs can boot from either FW or USB external drives.

PPC Macs can only boot from FW drives.

Again, mine work just fine and I see no difference in running from the Internal or the external as the speeds are both 5200 I believe...

Most laptop drives run at 5400 RPM. Most desktop drives are running at 7200 RPM.

With FW and USB, that's not the whole story. USB spec's out as faster (480mb/sec) than FW 400 (400mb/sec), but in real world tests I've found the overhead in the USB buss really hurts it's performance. FW drives and USB drives writing the same folders of files to a 7200 RPM internal drive show a 25% increase in speed over USB drives. That's why FW is the best interface for video camera's to be able to stream data to a Mac.

External FW800 cases with 7200 RPM drives actually perform as well or better than the 5400 RPM internal drive on my MBP. I booted from an OWC MiniStack V3 external FW800 500GB drive for years in my office. I used SuperDuper to clone the basic OS, emails, some documents, to the internal drive once a week so that I had the basics with me if I left the office.

As far as WD drives... There's no rhyme or reason as to which drives will work properly with FW. Western Digital came out with many firmware updates to their MyBook drives when Leopard came out. I viewed this as poor or minimal engineering to cut costs but the problems may actually be traced to design of features not necessary or wanted on a Mac. Many other brands of drives continued to work fine, as expected, with 10.5. Now I see new problems with WD drives and 10.6. It's really not a surprise that there are lingering firmware issues on these bargain products. In addition, I've seen other sites report that there are problems with WD's drivers for SL and that there are problems with a 'built-in' spin-down function on the drives themselves which can affect the drives' availability for Time Machine and even a booted OS. http://www.macosxhints.com/article.php?story=20090316190817357

So it would seem that some of the problems are being caused by a 'feature' and not a 'bug'. Since these 'features' require special drivers from the manufacturer I'll keep away from them. Apple's drivers are what I have to trust during upgrades and updates. Manufacturers can not be relied upon to provide timely updates, and users can not be depended upon to keep track of every proprietary driver on their systems. Any drive that comes with a setup disk or feature enhancements on in the protocol is suspect when upgrading to a new OS.

Luckily, I trusted my instincts and years ago went with OWC drives (MiniStack and Mercury) for all of my external drives, other than the ones where I bought simple external cases and installed the drives myself (they are also working perfectly with 10.5 and 10.6).

There are even reports that say Western Digital techs are not recommending booting from any external drive (they must mean theirs), yet we've been able to do this reliably with Mac OS, way before OS X, Firewire, or even USB.

At this time I still get occasional bare WD drives to repair systems with failed internal hard drives. They don't seem to have any of these issues, and are good generic hard drives. It looks like it's the features in the interface firmwares of their external cases that is the problem. If you remove the drive from a MyBook case and put it into a generic $30 case (and format the drive) you will probably have a good reliable drive for a Mac.

The Dude...

So there must be some incompatibility between WD hard drives and 10.6 because in several years of using them in external enclosures I've never once had problems with booting from them.

Does anyone know what a reliable internal drive would be for booting OS X from an external enclosure?

dechamp,

I have a Mac Pro with four internal drives. They are all Western Digital drives (WD7500AAKS). All of them are bootable with OS X 10.4, 10.5, and 10.6.

I have the identical WD drive (WD7500AAKS) in an external Icy Dock enclosure with OXFU924BS chipset.

The OWC Mercury drives use the OXFU924DS chipset, which I'm assuming is almost identical (if not completely identical) to the one in my Icy Dock enclosure.

Therefore, I can't figure out why my setup wouldn't work when a Mercury OWC setup would. Any ideas?

I would just be stabbing around here because I don't have one of those drives to test with. I work with a lot of drives, but I'm no engineer.

I've read that WD says their drives don't work well with Power Strips, if you can believe that (what, other voltages on the strip affect the drive?). There are other reports that some drives will mount if they are plugged in after the machine is booted (but that doesn't help booting).

I've also read of a problem with a set "Alias bit" that can be changed by downloading the 30 day trial of "Path Finder 5" - a Finder replacement program by Cocoatech: http://www.cocoatech.com/

They have a version for Leopard or Snow Leopard.

In addition, I've been doing some reading, and there is apparently a 'firmware' written to a 'service area' on the platter itself. This has been described by several on-line drive salvage companies.

I'm finding it interesting that these same drives and other Western Digital drives have many known issues with Vista: http://wdc.custhelp.com/cgi-bin/wdc.cfg/php/enduser/popupadp.php?p_faqid=1529&pcreated=1174506202

Also, since I tinker a bit, I'd be very tempted to enable the SSC pins on the drive itself to see if there is any difference in the way the drive acts: http://wdc.custhelp.com/cgi-bin/wdc.cfg/php/enduser/stdadp.php?p_faqid=1543&pcreated=#jumper and http://wdc.custhelp.com/cgi-bin/wdc.cfg/php/enduser/popupadp.php?p_faqid=3641&pcreated=1246906810 - What's the worst that could happen 🙂

It's quite a coincidence that with Vista these drives when used externally had problems with mounting and unmounting in USB mode, and dropping out in FW mode. When used internally they sometimes didn't boot a Vista system, even if it did sometimes in the past. Service Packs from Microsoft seem to solve some of the issues. I'm sure that these problems are related to incompatibilities with some motherboards and the way Vista drivers work. Could there be a correlation when compared to Snow Leopard? I've always assumed the external case was the problem, but maybe there are issues with the 'service area' firmware on the drive also?

I will continue to buy Hitachi (IBM design) Deskstar and Travelstar drives and Seagate drives for the near future. I've had problems pop up with just about every brand of drive, but they seem to be restricted to "era's". Years ago we called Seagates "Sea-crates" and FWD JackHammer drives were known as coffee warmers... During the SCSI era we used Seagate Barracuda's extensively and I sneered at IDE WD's. Progress...

I just use WD Diagnostic utilty to do full zero and extended test and that seems to help in both Vista/Win7 and Mac OS.

Even had one drive early Caviar 750GB that was fine data drive, found two areas needing to be remapped, and now works fine (I use to get BSOD after install and thought and tried every controller, new graphic card, different mouse and even keyboards).

Now I no longer test just zeroing a drive in Mac OS with any and all the utilities at my disposal.

And avoid WD MyBooks like the plague!

But the problem is that I can't even get the WD / Icy Dock to mount. So I can't zero it.

The plot thickens, because I distinctly remember that I was able to mount and boot from this external drive under 10.6. The problem started after updating to 10.6.1.

Badlydrawnboy wrote:
But the problem is that I can't even get the WD / Icy Dock to mount. So I can't zero it.

The plot thickens, because I distinctly remember that I was able to mount and boot from this external drive under 10.6. The problem started after updating to 10.6.1.

I wonder, did you try -

1) shutting down everything
2) unplugging your Mac and the WD drive from the mains socket,
3) waiting 30 seconds, then
4) replugging into the mains and rebooting everything.

I sometimes find my MyBook won't wake up (i.e doesn't appear on the desktop and iTunes can't find my Music (its on the external). I have found doing the above is all I need to do to cure it.

Wanna know a fun fact?

I have a 20" iMac 2.66
I recently updated to Snow Leopard and discovered that:

a) My external 1Tb WD works perfectly
b) My external 320Gb WD doesn't show up

Does anyone think there'll be a solution so I can use my 320Gb HD to backup or should I assume those 99 € are lost and I have to buy a new external HD to backup?

I'm not exactly happy so far because this drive is working, only 11 months old, and I haven't quite used it.

(1) Try: totally disconnect the drive and then reconnect. This may work.
(2) Does the drive show up as a gray icon in Disc Utility? If so, select it and then File | Mount
(3) If drives accept both USB and FireWire, try switching.
(4) Are both drives independently connected to your Mac?