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Hitachi 4TB Deskstar 7K4000 Hard Drive
Thanks to OWC for making the 4TB Hitachi Deskstar 7K4000 hard drive available for testing.
The 4TB Hitachi Deskstar 7K4000 hard drive offers a cavernous 4TB of storage with very high performanc. The huge capacity and ultra-high performance are available at a reasonable price.
A capacity of 4TB is enough for roughly 80,000 36-megapixel RAW files from a Nikon D800. Or many hours of video! With high quality JPEGs, it would be roughly 4-5 times that capacity.
The Hitachi 7K4000 is a 6 gigabit per second (“SATA 6G”) hard drive, backward compatible with 3Gbsp SATA also. The 6Gbps interface is welcome, and in theory could help on burst transfers, but is essentially meaningless as compared to SATA 3 Gbps for any application involving sustained transfer speed (most all uses).
Performance as a drive fills up
Looking for speed? A fast 4TB drive is the smart move, even if capacity requirements are much lower.
As a main drive
Don’t even think about using a 4TB drive as a main drive without a disciplined backup strategy. If you can store all your Stuff on one drive, think about what it would mean if that drive failed!
As a backup
With 4TB capacity, a simple and powerful backup strategy is to backup everything onto a single 4TB drive, for example cloning the Boot volume (system/apps) and the Master volume (data) of an MPG Pro Workstation to an external drive (e.g., BootClone + MasterClone, so as to have a fully bootable single-drive backup of all your Stuff. And perhaps even a Time Machine backup volume on it as well, for data redundancy and a different feature set.
The Hitachi 7K4000 was tested in the Mac Pro 3.33 GHz 6-core, on the internal SATA bus. Four (4) samples were tested.
The drive was tested using the DiskTester command line version as follows:
disktester fill-volume volume-name
The DiskTester fill-volume command writes 1000 files to fill the volume to 99% capacity, then reads those 1000 files back while checking for data errors. The resulting data can be graphed to characterize the performance across the drive, as seen below.
Four units of the Deskstar 7K4000 were very quiet in my Mac Pro during sequential I/O. Some spinning noise can be heard with four drives, but it is at a low level.
Single drive sustained transfer MB/sec
Sustained transfer speed is the metric most important for most users, and especially for opening large files in Photoshop and similar.
Write performance declines very consistently across the drive; see Larger Hard Drives Are Faster Than Smaller Ones.
The graph below plots both the 7K4000 and its slower sibling, the 5K4000 Coolspin.
The 7K4000 is considerably faster than the 5K4000 Coolspin, making it the drive of choice for any user concerned with performance. The 7K4000 is the fastest hard drive tested here at MPG as of April 2012.
Click to view a larger graph.
Four samples compared
Using the DiskTester run-sequential command, each drive was tested for speed. The results are more consistent than any previous Hitachi Deskstar yet tested here at MPG.
Sample 1: 159 161
Sample 2: 159 160
Sample 3: 159 161
Sample 4: 159 160
RAID-0 striping for faster performance
Single drive performance is outstanding (for a single drive) but only to about 2/3 of capacity. Speed then then declines rapidly.
Utilizing a two-drive RAID-0 stripe for one’s Master volume bumps up performance greatly.
A 2-drive RAID-0 stripe is the default configuration for the Master volume in an MPG Pro Workstation, precisely for that reason: performance doubles.
While doubling the capacity to 8TB is a bonus side-effect, the 2-drive stripe when completely full is still as fast as a single drive when empty. This meets the “fast enough” principle for making a workhorse machine feel fast and responsive even as needs grow.
Ultra-demanding users might consider a 3-drive or even a 4-drive stripe, but that should be considered only for exceptionally large files (diminishing returns), and also raises the reliability concerns (failure of any drive in a stripe kills the volume).
A 3-drive stripe shows a very attractive level of performance for those needing both high sustained transfer speeds as well as monster capacity (12TB).