[G4] SATA Cards & IDE Controllers

[Mike Bechtold]

Robert:

The short answer is that the SATA card takes over the 
function of the IDE controller, which you then don't 
need any more. 

The longer explanation is that the Serial ATA ("SATA")
disk interface has two advantages over the Parallel ATA 
("PATA" or "IDE") disk interface in the Powermac. The
first is speed; SATA 1 is three times as fast as IDE,
and SATA 2 six times. That's not the whole story, of
course; the rest of the system has to be able to keep 
up with that rate, and you probably won't see any 
increase in speed with SATA 2 over SATA 1. But I sure
see an increase with SATA 1 over IDE, especially given
that the Powermac IDE controller isn't that fast even
as IDE controllers go.

The second advantage is that there is no 128 GB address
space limit on a SATA card as there is on the Powermac
IDE controller. So you can use (today) 1.5 TB drives,
and see all of that space. There are hacks to get 
around this limit on the IDE controller, but none for
speed.

The SATA card simply plugs into any open PCI card slot,
and has SATA connectors to hook up compatible hard 
drives. You cannot connect your old PATA drives to a
SATA card, so you'd have to replace them. OWC carries
SATA cards that will support both 2 and 4 drives per
card. So you can see that you can add a LOT of new
drive space if you need and want to. 

That being said, you can use both PATA and SATA drives
in the same machine. The limitation becomes the power
supply, its capacity, and the number of power supply
connectors available for more drives. My G4 has 
physical space for four drives, but only three power
supply leads. There are adapters available for this
function, as long as there's enough current available
for all the stuff in your system. And of course, every
time you access a PATA drive in a mixed system, you 
sloooooowww down. 

So right now in my system, I've removed my PATA drives,
and replaced them with a single 160 GB SATA, which can
be had fairly inexpensively. For me, it's been a great
upgrade.

- Michael B. in Cincinnati