How do you know what version Mac OSX is on ANOTHER drive?

Open the Startup Disk pane of System Preferences and see what's noted for that drive, or retrieve the build from the System/Library/CoreServices/SystemVersion.plist file.

(49390)

One possibility for why the machine won't boot is also that the OS may be a version that was used before your machine was made. Mac's can not boot from an OS from before they were manufactured. In fact some machines require a specific version of an OS like 10.2.4 or 10.5.2 and will not boot from 10.2.1 or 10.5.0

I've seen this on PowerMac's with upgraded video cards that were not considered with the proper video drivers on earlier releases of the OS.

BTW, what OS are you running? Your profile says 10.5.7?

One of the reasons I don't bother using eSATA cards and drives is that they are very spotty with booting MacOS. Apple does not specifically support this, just Firewire and now USB also for Intel Mac's.

Some cards have advertised that they can boot a Mac, but OS's change and they do not...

According to this page, that card was designed to be able to boot MacOS on a G5 or PPC Mac: http://www.amug.org/amug-web/html/amug/reviews/articles/firmtek/2se2e/

I don't know if they support this on an Intel Mac with Snow Leopard. In addition, Firmtek has new drivers for the card and Snow Leopard: http://www.firmtek.com/download/

but if you need drivers to see a card, or the drives, then it probably won't be able to boot a Mac.

Here's the write-up on their new driver: http://www.storagenewsletter.com/news/connection/firmtek-apple-snow-leopard-comp atible-driver - The word "boot" is not on the page, so I'm not sure.

Interesting page about eSata and Snow Leopard: http://forums.creativecow.net/thread/8/1051087

Why mess with this? Well, I got the HDDs and the enclosure from my previous PPC, so I'd like to make use of it all without $pending again.

I don't see any problems with using the card and drives on your new Mac. Hardware is too pricey to just leave behind if you can't help it. With the new drivers I suspect you'll be able to use your drives, I just don't think you'll be able to boot from them if the interface card requires drivers. They should still be very fast storage devices, and probably reliable due to the ongoing support the vendor has provided.

I went through the same type of issue when I bought my Dual G4 1.42 Tower (upgraded from a Quadra 840AV 🙂 ). Several of my devices were SCSI (I was into SCSI Wide/Fast drive arrays at the time for video capture), and I was able to use an Adaptec card for scanning for several years with Jaguar and Panther. I'd spent quite a bit of cash to ensure high quality and performance and didn't want to loose all of the investment. Eventually the SATA hard drives and other USB and Firewire replacements became so cheap and performance improved enough that loosing SCSI with Tiger was not a big deal. I do think I should get about 5 years of hardware compatibility with most products and I keep older Mac's around for dedicated services as long as they aren't a costly maintenance issue.

Like I said at the first, I don't use eSATA, so I'd think you would want to start another thread based on these performance and use issues. There are probably quite a few other users with eSATA drives that are not checking this thread due to the title.

We all tend to look down the list of questions to see if there is anything that we have some experience with. I don't look at some questions at all until they are marked "Solved" because I don't have a clue about the problem, and just want to learn the answer 🙂

Good Luck.