Why doesn't my Mac Pro see my new 4TB SATA drive?

I purchased a Seagate ST4000DX001 4TB SATA Hybrid Drive (SSHD) and installed it into my Mac Pro (six core 3.33 GHZ MacPro5,1) in one of the internal SATA drive bays. However, the system didn't see it at all. Disk Utility didn't show the drive for me to format and the SATA Devices section under Apple System Profiler didn't show the drive listed at all.

The drive works because if I put it into a USB3 enclosure then it works, but since the Mac pro only has USB2 it's pointless for me to use it in a USB3 enclosure.

Why doesn't my Mac Pro see my Seagate 4TB SATA SSHD drive?

Solution 1:

You've done all that I usually do to troubleshoot this in that you already know to use System Profiler to check the SATA bus for devices.

I would reboot the system and reset the NVRAM twice (keep holding the keys down and you'll hear the chime twice) and then re-check the profiler.

Sadly, if the controller doesn't make that device available - you'll need to use it connected to a non-optimal bus while you work with Seagate and/or Apple tech support to determine at a device driver level what settings need to be tweaked or updated to expose that particular drive to your Mac. Let's hope someone has the same drive and can either confirm or deny for their OS X level that the drive works for them.

Solution 2:

I recently installed a 3 TB drive in a drive bay of my 2008 Mac Pro. When I rebooted it was not recognised and required formatting. However Disk Utility formatted it as a “Logical Volume Group”. I could not set the partition and GUID option and it was not showing the full capacity of the drive.

I Googled the issue and found that 10.8.4 and 10.8.5 have a bug which was causing this problem to occur with drives of 3 TB and greater capacity. The solution was to boot from an earlier version of OS X. I booted from a Snow Leopard boot drive which I keep on a USB Flash Drive and used Disk Utility to successfully re-format and partition the 3 TB drive. I am not sure whether the bug is still present in Mavericks.

I was running 10.8.5 when I encountered the problem I described above - drive not recognised but Disk Utility did offer to format it. However the normal format options were not available with "Logical Volume Group" being the only option.

I did not have a boot volume pre 10.8.4 but did have a Snow Leopard boot volume. When I restarted my Mac Pro with this Snow Leopard volume I was able to use Disk Utility to set the drive to one partition and GUID format. When I rebooted into 10.8.5 the drive was recognised as a normal volume and I have been using it for my Time Machine backup ever since.

While you mention that your problem is that Disk Utility does not see your drive, if you are running 10.8.4 or later it may still be worth trying an earlier version of the OS.