I've just got four Seagate 500GB 7200.11 w/32MB cache drives. I want to get a new external enclosure to use some of the drives. I probably will have to hook up my new enclosure to a 5-year old system that supports only PATA. I am using the old exclusively to file transfers over the net......

Two enclosures I am eyeing on.
3.5" HDD enclosure w/ eSATA, 1394a, USB2.0
3.5" HDD enclosure w/ eSATA, 1394a, 1394b, USB2.0

My question is really about the enclosure's support for eSATA and 1394b. As my motherboard supports only PATA drives, is it logical to think that both the eSATA and 1394b features are useless to me? My motherboard has only 1394a ports and the new 1394b's connector is different from that for 1394a.....that is why I think 1394b is also useless in my case.

My old motherboard - Gigabyte GA-8IRXP
http://www.gigabyte.com.tw/Product [...] uctID=1298

Need some hints here...

Pick up an eSATA expansion card that goes in your pci slot. Problem solved.

http://www.techbuy.com.au/products [...] 710372.asp is an example

That surely solves the eSATA part problem. Thanks for that!!!

Well up till now, I am big fan of 1394 interface - 24x7 and always rock solid and stable transfer. So I may also want the enclosure with 1394b as well. For this to work, I will need put another 1394a+b expansion card to my m/d PCI slot. Correct? Just following the same logic LOL

If you put in a new 1394B controller in a PCI slot, probably wise to forget the eSATA. Of the two, 1394B is faster than eSATA for data transfer rate. I assume that the external case you propose has controller(s) for the HDD's you will put in there, so that this controller takes care of communication along the 1394B interface to the computer. Maybe it comes with a driver to let the computer deal with the external case as a HDD resource?

You should know, however, that eSATA is second only to 1394B for data transfer rate, and it is a little faster than 1394A. So an eSATA controller, with no 1394B, might be almost as good.

Not true. 1394b speed is 800Mb/sec, eSATA is 1.5Gb/sec (over twice as fast as 1394b) or 3.0Gb/sec (over 4 times as fast as 1394b).

Also, 1394b requires some processing overhead (not as much as USB) which slows the theoretical transfer rates down. eSATA is native to both the computer and the hard drive, and requires no additional processing overhead.

You will get full hard drive speed from eSATA, just like you would get if the hard drive was running on internal SATA. eSATA and internal SATA are in fact, the same, with slightly different cable and electrical design for eSATA that allows longer cables.

Again thanks for everyone's inputs.
I found this article addressing every concern in my initial inquiry. Hope it will be useful to other members as well.
http://compreviews.about.com/od/storage/a/eSATA.htm