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Sustained Transfer Speed — 2011 MacBook Pro 6G Port
Related: Apple macOS, diglloydTools, DiskTester, laptop, MacBook, MacBook Pro, Other World Computing, SSD, storage
These results are DiskTester fill-volume.
Results (zeroes) — 240GB model
The drive was filled with all zeroes using DiskTester fill-volume.
Write: 479.9 MB/sec*
Read: 506.4 MB/sec
* Excluding the last few GB. The slowdown at the very end is NOT the SSD, rather, it is a Mac OS X file system inefficiency when the drive gets near full; it happens with all drives.
Outstanding! These are numbers through the Mac OS X file system, not artificial driver-level numbers. So this is what real programs “see”.

(Disktester fill-volume test on 2011 MacBook Pro 15" 2.2GHz)
Results (zeroes) — 120GB model
The drive was filled with all zeroes using DiskTester fill-volume.
Write zeroes: 469.8 MB/sec*
Read zeroes: 508.1 MB/sec
Write incompressible: 172.6 MB/sec*
Read incompressible: 449.6 MB/sec
* Excluding the last few GB. The slowdown at the very end is NOT the SSD, rather, it is a Mac OS X file system inefficiency when the drive gets near full; it happens with all drives.
These are numbers through the Mac OS X file system, not artificial driver-level numbers. So this is what real programs “see”.
The Sandforce controller used in the OWC Mercury Pro series (and all brands using the Sandforce controller) use compression to decrease the wear on the flash memory. This exerts a performance penalty for incompressible data, which includes most digital camera image files, JPEGs, video, sound files, etc.

(Disktester fill-volume test on 2011 MacBook Pro 15" 2.2GHz)