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Q:  What Macs natively support large IDE drives? (over 128GB formatted)

A:  I duplicated a past FAQ item here ("why does my large drive (over 128GB) format to only 128GB") since some missed the point of that posting - which macs natively support big drives and options for macs that don't.

Mac towers before the 2002 Quicksilver models do not natively support large drives on the onboard IDE (i.e. drives larger than 128GB will be limited to 128GB formatted regardless of the number of partitions used.) The 2001 Quicksilver and older Macs (Digital Audio, Gigabit, Sawtooth, B&W G3, Beige G3, etc. as well as iMacs before the iMac G4 model) do not have big drive support. (See below for options to add support).
As noted in drive database reports, the main site IDE topics page, Hard Drive section article, etc. - the 2002 QS, iMac G4, eMac, Mirror Drive Door and later models (including the G5 tower and Xserves of course) have native big drive support (with drives formatted in disk utility in 10.2.x and later).
For macs w/o native big drive support - options like Intech's drivers, a Mac PCI IDE card w/big drive support, or a Firewire case with bridge board that has big drive support are options. (see below)

(from the March 24th, 2004 www.xlr8yourmac.com news page)
Intech wrote they've posted an OS X extension/driver which enables 48bit addressing/big drive support for older macs onboard IDE. (Their previous Speedtools Disk Driver enabled big drive support for OS 9 users.)

" Hey Mike
I thought your readers would be interested to know that there is a finally a driver solution for all those people out there trying to run ATA extended capacity drives (over 128 GB in size) under MacOS X on their G3's and older G4's. (QS 2002, iMac G4, eMac, MDD and later Macs have native big drive support, but not older models)
We just finished releasing a driver which enables this support on those machines
http://www.speedtools.com/ATA6.html.
We've verified support all the way back to a Beige G3/233 and tested several languages as well. We've included an intelligent installation and removal utility which allows simultaneous installation/removal on multiple bootable volumes. Combine this product with our Hard Disk SpeedTools for MacOS 9, and you've got a full OS 9 & X Hi-Cap solution!
Christopher P. Karr
V.P. Engineering
Intech Software Corporation
http://www.speedtools.com/ "

NOTE: See the limitations and notes on the linked page above and fully read the PDF readme file on "safe partitioning", etc. with this OS X extension. (Regarding booting from CD, OS X install CDs, Disk repair CDs, etc.) Also note they don't support the B&W G3's primary IDE bus (I wrote to ask if this includes the rev B B&W G3s with revised IDE chip - he later replied they had only tested with rev 1/rev A B&W G3s which have the flawed IDE chip.)
See below for older info on other options for big drive support:

(previous info from 2002 follows)

Note: Apple's August 2002 G4 "Mirrored Drive Door" systems (and Xserve) natively support 48-bit addressing to fully utilize large drives (Hitachi, Western Digital and Maxtor now sell 'big' drives - 180, 200, 250GB and one of Maxtor's latest drives have capacities of 320GB. Larger drives are sure to appear.)
And despite the Apple kbase doc noting on the MDD and Xserve models natively supporting "big" drives (without addon drivers for controllers) - owners of Quicksilver 2002 and iMac G4s have reported native support (full capacity) with large drives formatted in OS X 10.2.x. (Also the current eMacs have big drive support - search the drive database here for the latest reports.) See this article linked off the main www.xlr8yourmac.com IDE and Systems topics pages. (Although the drive database is updated more often for reports, this page shows a sample of past owner reports on those mac models with large drives.)
Also note that current eMac owners also have reported native "big" drive support.

In the past you needed either a PCI IDE controller (i.e. Acard ATA/100+, ATA/133) or Intechusa.com's (OS 9 only) Speedtools v6 drivers, or a Firewire bridge board with firmware that supported 48-bit addressing.

(older/previous info follows from shortly after Maxtor released the first "big" IDE drive - their 160GB model - a few years back)

Maxtor was the first vendor to release an IDE drive larger than 128GB, their 160GB ATA/133 model. (now there are many other choices of even larger drives, 180GB, 200GB, 250GB, etc.) As noted in past drive database reports and main site news items, an ATA/133 compatible interface is required (which uses 48-bit addressing) to be able to use the full capacity of the drive - or a driver that supports 48-Bit addressing. (If used with an ATA/3, ATA/33, ATA/66, etc. card the drive max size is limited to 128GB or so without a 48-bit disk driver.)
Intech's 3.5 Disk Driver update added support for large drives noted in the April 2002 www.xlr8yourmac.com news which had a Q&A with Intech on SpeedTools 3.5 Update Large Drive Support - but as noted there - to date they have no OS X support (yet at last as of late 2002).

If you own an Acard ATA/100+ (or ATA/133 - SIIG ATA/133 cards are also Acard based) Mac IDE PCI Card, there is an update that is reported to allow full use of the >128GB drives. (This chip is ATA/133 compatible). A reader noted in a Jan 2002 drive database entry for his Maxtor 160GB drive that the Acard OS X driver update for this Acard ATA/100+ card allowed full use of the 160GB drive. (See the Jan 4th, 2002 news page for details. You can also see Brian's report by searching the Drive Compat. Database by selecting Maxtor as the drive brand, HD as drive type, IDE PCI Card as interface, Dual G4 as mac model, and OS X as OS version.)

(FYI - Readers have reported the SIIG ATA/100+ and Miglia ATA/100+ Mac IDE cards are really based on the same Acard controller, so this tip may also work for those card owners.)

Reminder on Drive Size vs Formatted Capacity: For those that missed the older FAQ item here, remember no drive formats the the "rated" size. This is due to the fact the drives are rated using decimal (base 10) numbering system vs the computer using binary (base 2) numbering. [I.E. 1K in decimal is 1000, 1K in binary is 1024, There's an older FAQ item in this section that covers this in detail. (See the question titled How come my new XX GB Hard Drive is not XX GB after being formatted?.)