External hard drives not recognized by Mac...

I am having the same issue wd external drive on my mac book pro and also a seagate 
they both work intermediately on a firewire 

Fixed- I purchased one of the following esata cards with the JMB360 chipset and it worked in my brand new Macbook pro 17" right out of the box.   My other eSata from SIIG, inc would not mount any drives or accept any drivers.    So the silicon based eSata's must have some type of hardware conflict with Macbooks.  (P.S.  I purchased the one from Best Connectivity for $20).   These cards all use the JMB360 Chipset:

• ApioTek (1 port card) (EXTREME eSATAII Express Card)
• Best Connectivity (1 esata)
• GWC Technology (GWC BS1020) (2 ports)
• nGear (Moved to the Sil3132 chipset list. See my more recent post about this)
• PPA Int’l (2 ports)
• VC (an original brand of Vintage Computer Inc.)
• Syba (1 Port)
• Sunix ECSA24J (Discontinued)

yo so i boght a new eSata card (see above post) and ended up just using disk utility to format my 4 750 GB WD barracudas into 2 groups. one was stripped and then raided the whole group of 4, so basically it is just mirrored, but it gave me a faster transfer rate. it works fine now, it just kicks off my drive sometimes if its idle for a day or two. i make sure to boot the external raid drives first and shut them off after the machine is off. its pretty tempermental at times, but its worth the uncomressed 1080i editing i do. rendering is so much faster now, so glad i got support on it from DatOptic whom i purchased the raid from....see the below review i gave of them.

I am an editor and have clients like Fox, Universal, The History Channel, Animal Planet, and others. I came to DATOptic looking to resolve my storage crisis; too much media, not enough space and no where near the speed I need. I purchased the DATOptic sBOX-P 5 drive eSATA RAID tower with 4 x 750GB WD drives at a killer price. But I didnt come to this decision lightly, I searched around...a lot. And you guys had the goods, the knowledge, the technology and the support I needed to get my 3TB drive up and running like whoa! And on top of that in the middle of setting up my RAID I decided to go to Leopard and you gave me the 'Oh, no problem' answer that I love. You guys have your **** together. I had a few hickups setting up my RAID, and Sam the man from DATOptic came to my rescue. I e-mailed, he called me, fixed the problem over the phone, then called later that week to make sure it was all good in the hood. Are you guys from the Midwest with that work mentality??? Cause you sure as hell don't see that type of support here in LA. Really, you guys are my go to guns now. I already sent another editor your way for his storage needs, too. Much appreciated!

Thanks for your help Sam!

Hello :-)I had to cut some plastic off the housing of the cable's connector to make it go all the way into the express-card.  Having two Raid-striped 1TB drives on a noname Silicon Image based Express Card performing about 115 MB/sec transfer on a early-2008 MBP with Leo 10.5.5.
Greetings, Drix

This is not quite a solution... but it is hope.

I never got my WD external drive to do anything with Mac OS X, but I did get it working in Windows Vista. The only thing was this: if I booted up my computer with the harddrive already running, the BIOS would get locked up. So, I simply had to wait until the computer was already booted up before turning on that eSATA hard drive. After that, the drive ran like a normal firewire/usb hard drive would.

In fact, it ran almost exactly like any of my other firewire/usb hard drives, which frustrated me. The whole point of me using this technology was for an abnormally fast transfer rate. Not happening... it runs no differently than anything else. So, after a while, I decided to scrap the whole eSATA thing and just run the WD drive off of firewire. It's apparent that the computers (even the best of the best Mac's) are not up-to-date with this technology.