[SuperHard]

I'm going to add a hard drive to my dual G4 450 MHz (aka sawtooth, I think). At TransIntl, I see you can get an IBM Deskstar 180GB Ultra ATA-6 for $189. I'd like to get as fast a drive as possible and I think this one is about as fast as they come (IDE style anyway). But what type of connection within my mac will support the fastest transfer rate? Should I get an Ultra ATA-? PCI card? Would transferring through PCI negate the Ultra ATA benefit? I don't know what size bus connects to the PCI slots. Alternatively, is an external firewire drive hands down the speed champ versus any internal drive I could put in this computer?
Acutally, do I need to go with firewire to add a drive of this size. In my searches I saw some notes about the drive size limited to 130GB on an ATA controller. Currently the computer only has one drive in it, (20GB). And one free PCI slot.

I'd really appreciate any clarification you can offer along these issues!
thanks!

[CIA]

First off, regardless of what PCI card you get, you really only need ATA-100, ATA-133 will show you no real world performance increase. That said, I have a QSDual800, with 1 ATA133 RAID card and one ATA 133 normal card powering my drives. In hindsight (always 20/20) I could've gotten away with ATA100, since my RAID is using ATA/100 drives, (Western Digital 120GB Special Editions) and my ATA/133 drive is only 5400RPM. The added cost of ATA/133 is a ripoff these days, esp with serialATA on the horizen.
If you really want speed, get a nice cheap Mac Compatable ATA100 card and just hook it up. Make sure you get one that works with ATA6 drives though.
Or...
You could get a firewire 800 case and a firewire800 PCI card, but that's $$$.
I'd just go with an internal drive and a PCI ATA100 card.

Finally, what else is in your other PCI slots? You could run the chance of saturating the PCI bus and slowing things down. I've never really heard of this happening, but it could.