Deskstar 5k4000 4TB drive only shows up as 1.8TB in Disk Utility

You need a case or a dock with new chips that support 4TB drives.

If it doesn't say that it supports 4 TB drives, then it doesn't.

These cases are quite recent, will cost more, and won't be on sale :-(

Small update and correction:

I have an older NewerTech Voyager Q dock with ports for USB2, Firewire 800, Firewire 400 and eSATA.

The first 3 of these only support up to 2TB drives. I didn't have an eSATA connection to test the 4th.

OWC <support@macsales.com> said none of the ports supported more than 2TB.

Nevertheless, I ordered an el cheapo Chinese 2 port flush mount eSATA expresscard.

The Voyager dock DOES support my Hitachi 4TB DeathStar using the eSATA port.

So does SATA in my very old Apple Time Capsule :-)

ps. The eSATA port on the Voyager is recessed to far and didn't work with 3 of the 4 cables I had.

All 4 cables were too stiff for use on a laptop. Pay extra and get a soft flexible cable.

Thanks for blessing my reply.

I have a MacPro 1,1 I tried to connect a new Hitachi 4 TB drive with a Voyager unit from OWC. Disk Utility only recognized it as a 1.8 TB drive when connected with FW800. I then connected it with an eSATA cable and it recognized and formatted it as a 4 TB drive correctly.

This thread was most helpful in allowing me to recognize that solution.

Flag the post that helped you as "This helped me" and you might get another reply :-)

Only the original poster can flag a helped or solved award. 🙂

Perhaps like would do

🙂

Rosewill eSATA/USB 2.0 dock with 4Tb HGST drive worked great using either interface under OS X 10.9 (Mav)

With 10.10.1 (Yos) the 4Tb HGST is seen as 1.8Tb and of course will not read the data on the drive.

This does have something to do with drive size because 1Tb and 2Tb drives mount as expected under 10.10.1

Apple driver update please!

Drivers for 3rd party peripherals are written and supplied by the manufacturer of the peripheral.