Sustained Transfer Speed for Large Transfers

OWC Mercury Aura SSD for Mac Pro: 1TB about $899, 2TB about $1479.

DiglloydTools DiskTester was used with the fill-volume command to fill the entire 2TB capacity. The test was performed first with zeroes, then with incompressible data because some SSD controllers slow down with incompressible data.

disktester fill-volume --xfer 128M
disktester fill-volume --xfer 128M --fill randomblock

Incompressible data is all but the same speed for reads. And for the first ~1.3TB, write speed with incompressible data held at about 620 MB/sec. Thereafter, write speed dipped to the ~530 MB/sec level for the remainder of the capacity. Well, this is a worst case scenario unlikely to occur with any real usage (filling 2TB of SSD with totally incompressible data in 90 minutes!).

These figures exceed the fastest SATA SSDs easily, though not as fast as Apple’s own SSD (though real world performance past 500 MB/sec hardly matters for most all apps). Moreover, the transfer speeds under more ordinary loads and transfer sizes are excellent.

Clearly to have this kind of performance in one internal 2TB drive is a big win. And if the alternative is an Apple 256TB or 512GB internal SSD reaching capacity, then either the 1TB or 2TB options are a welcome path.

Averages across the entire 2TB:

Zeroes: 687 / 728 MB/sec, standard Deviation: 17.5 / 0.70 MB/sec
Incompressible: 591 / 721 MB/sec, standard deviation: 42.0 / 0.93 MB/sec

Real world speed through the OS X file system, e.g. speeds a normal app can access (not unrealistic low-level driver-level performance).

OWC Aura SSD for 2013 Mac Pro: sustained transfer speed with large transfers