Hard Drive size limit? 128 gb?

There is no such restriction with 10.4. What you are seeing is the restriction of the ATA controller inside the case that is attached to your drive. The ATA standard before ATA-6 only used 28 bits for addressing so this limited drives to approximately 128 gigabytes.

You need to get a case with an ATA-6 supported controller or live with the 128 gigabytes restriction.

For more on that, see my post here:

http://discussions.apple.com/message.jspa?messageID=1388385#1388385

Hold on a second, a Powerbook G4 1.67 Ghz should not have that ATA restriction. However if you have an old hard drive case you are hooking it up via, you may have that restriction. If that case is older than 2002 it may be an issue.

I have a 300 gb hard drive in an external enclosure. I've formatted it for extended format but it only shows 280 Gb. Why doesn't it see the other 20 Gb? I know I have lots of room, but 20 Gb is a lot to lose.

I also lost 10 Gb in a 160 Gb drive. I expect to lose some when I format the drives, but why is the amount of space lost smaller than 10 Gb increments?

Is this something to do with my powerbook or Tiger?

The 300 Gb drive has USB 2.0 & FW 800.
The 160 Gb drive has only USB 2.0 connections.

Any insight would be appreciated.
thanks

Powerbook 15 in G4 1.25 Ghz Mac OS X (10.4.4)

Bruin,
Welcome to Apple Discussions!
It isn't so much lost, it is how the hard drive industry counts bytes when they estimate how much you'll be able to format it. On much larger drives that number gets greater. Though this is a good article which explains it:

http://docs.info.apple.com/article.html?artnum=30065

Ok, that explains quite a bit. I did the calculations and they work out fine. So I am seeing the full disk space...it's just a difference in how the bytes are counted.

Thanks very much!