Jump to content

Volume size limits under HFS and HFS+

Recommended Posts

With thanks to defor for compiling this information over here.



These are the limits for HFS support on Macintosh System/MacOS:

(I had to dig a bit to find this)


Maximum HFS partition sizes by OS version:

Macintosh System 1.x - 7.1.x : 2GB1
Macintosh System 7.5.x : 4GB1
Macintosh Mac OS 7.6.x - 8.1 : 4GB (68K without SCSI Manager 4.3)2
Macintosh Mac OS 7.6.x - X 10.5.x3 : 2TB1 (SCSI Manager 4.3 on 68040 or later, excluding Quadra 630 and 68040 PowerBooks4)
Maximum HFS+ partition sizes by OS version:
Macintosh Mac OS 8.x - X 1.x : 2TB4
Macintosh Mac OS 10.2.x : 8TB4
Macintosh Mac OS 10.3.x - 10.5.2 : 16TB4
Macintosh Mac OS 10.5.3 - CURRENT : 8EB4
in the end, you'd be hard pressed to find a consumer SSD that is larger than 2TB, so the reality is:
HFS on up to 2TB drives works fine. IF you have a computer that can support it (i.e. 68040* or later, and System 7.6 or later)
A Mac IICI won't support SCSI Manager 4.3's volume size increase, so in theory, the max you could ever see is a 4GB volume.
I personally have two Power Computing PowerTower Pros with Sonnet SATA cards in 7.6.1, with a 2TB SATA drive as the boot volume.
YES, minimum file size is HUGE, but it works.
If you insist on photo proof, I'm more than happy to oblige.

1 http://classroom.synonym.com/size-limitation-hfs-format-hard-drive-15364.html ( HFS Volume Limitations)

http://lowendmac.com/2014/system-7-5-and-mac-os-7-6-the-beginning-and-end-of-an-era/ ( In Defense of 7.6)

3 http://www.computerworld.com/article/2467506/mac-os-x/losing-legacy-data-to-snow-leopard.html

https://tidbits.com/article/1756 ( Hardware support)

5 https://support.apple.com/en-us/HT201711


Link to post
Share on other sites
  • 3 years later...

Maximum Bootable partition size by OS version:

Macintosh Mac OS 1.x - 9.x : 200GB6


Maximum Bootable partition size by ROM Errata:

Power Macintosh G3 (Beige) Mac OS 10.x : 8GB (And the extents of this partition must land within the confines of the first 8GB of the actual Disk)


This means that while even though you may create a 2TB partition on a SCSI Manger 4.3 system, it will not be bootable.

i.e. partitioning a larger drive into a 200GB "Boot Drive" and a 1.8TB "Data Drive" will work fine.


As usual, these are all partition size limitations. Actual Drive limits will still apply first.

i.e. an LBA32 ATA controller, like those found in most systems before the Power Mac G4 (Mirrored Drive Doors)6, will limit the drive's actual size to 137GB.


There are third party software solutions for allowing LBA48 support in these cases, but because the limitation exists in hardware, the solution is only viable once the OS is loaded, so the bootable partition's extents muyst be within the LBA32 region similar to the Power Macintosh (Beige) G3 limits.

Many SIL3112 SATA and ATA/133 PCI upgrade cards properly support LBA48, and because of their presentation in hardware as "SCSI" devices, HFS/HFS+ partition size limits can be achieved without issue.


6 https://support.apple.com/en-us/HT2544

Link to post
Share on other sites
This topic is now closed to further replies.
  • Create New...