I heard somewhere that the maximum HDD size that my Mid 2010 Mac Pro can handle is 4TB. Is this correct? If not, how big can I go?


It's not that they can't address a larger drive, it's that the screw holes don't fit the 'sleds' that the drives are mounted on.

OWC sell replacements - http://eshop.macsales.com/item/OWC/MPRODBKTLG6/ though I have no idea if they ship outside the US, or indeed if that would be worth it.

Standard sled - 4 mount points.

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6TB compatible sled - 6 mount points

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Pics from OWC [no affiliation]

  • Does this mean that I am correct in thinking that 4TB is the biggest I can go without replacing the sleds as well? – PSDuckie Mar 2 '16 at 16:35
  • or doing a little DIY, yes. Though, I have heard reports of some 6TB drives being made now with holes in the old standard locations. – Tetsujin Mar 2 '16 at 16:36
  • Without modification, you can get 4x4TB in there. With a little, but not much extra jiggery-pokery, you can also get an SSD in the spare optical bay, or even one on the PCIe bus. I've 6 drives in mine, 4 HD, 1 SSD, 1 superdrive. – Tetsujin Mar 2 '16 at 16:41

The OS X HFS+ Operating System will max out around 8 EB (Exabytes)

To put that into perspective:

8EB = 8,000 Petabytes

1 Petabyte = 1,000 Terrabytes

1 TB = 1,000 GB

In other words...

8 EB = 8 Million TB or 2 million of your 4 TB Hard Drives. I hope you have room under your desk.

However, a 4 TB drive will easily be installed or you could opt for one of the new 8 TB Helium Drives.

  • Right now I have no hard drive on the Mac Pro, and fixing that is why I'm asking the question. – PSDuckie Mar 2 '16 at 16:36
  • The question is not about the supported file system size. Several Mac models had some limitations regarding hdd size and/or form factor due to limitations/bugs of the hdd controller or design height. – klanomath Mar 2 '16 at 16:41
  • @klanomath Does a Mac Pro take a 3.5 inch drive? Then what is the issue with design height? Can you point to a tech document referencing the limitation? 48bit LBA supports about 128PB so are you saying that Apple somehow doesn't conform to the SATA Standard? – Allan Mar 2 '16 at 16:46
  • @Allan Apple officially supports 2 TB (and smaller) drives in this Mac Pro. The asking person wants to know if drives > 2 TB are also supported. Answering this question positively I would provide either own experience and/or other persons experiences and/or a technical document published by Apple/3rd party. A well known example of an "artificially" limited Mac is the Apple Power Macintosh G4 933 (QS 2002)! – klanomath Mar 2 '16 at 17:07
  • @klanomath You mentioned "design height" and "limitation and bugs in controller" That's what I am responding to. Apple "official support" was written when 2TB was the largest. A SATA 1 controller can handle at least 128PB and HFS+ can handle 8EB. Why wouldn't it support it again? – Allan Mar 2 '16 at 17:16

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