Mercury Accelsior 'E2' eSATA 6G Speed with HDD / SSD

See the other pages of this OWC Mercury Accelsior PCIe SSD review.

The OWC Mercury Accelsior E2 sports dual eSATA ports, a boon for anyone looking to have both eSATA connectivity and a PCIe SSD; on a 2008-2012 Mac Pro this saves a precious PCIe slot (there are only three open slots).

Fast external SSDs using 6G SATA ports

The eSATA 6G ports on the Accelsior E2 allow connecting any two eSATA devices.

• External SSDs or hard drives can be connected (two SSDs, two hard drives or one of each).
• External SSDs on the Accelsior E2 SATA 6 Gbps ports run much faster than the internal 2009-2012 Mac Pro SATA ports ( internal ports are 3 Gbps, Accelsior E2 eSATA ports are 6 Gbps).

Accelsior E2: eSATA speed to external Mercury Extreme Pro 6G SSD

An OWC Mercury Extreme Pro 6G SSD (480GB) was installed in an OWC Mercury Elite Pro Mini USB3/eSATA case (eSATA was used of course). This case is pass-through for eSATA (not a bridge board), so it should run the SSD at full speed.

External SSD performance using the Accelsior E2 eSATA ports is outstanding, reaching speeds approaching the limit of the SSD itself.

Context, the same 6G SSD on an internal Mac Pro SATA port will run at no more than 275 MB/sec (typical) versus the 450-470 MB/sec externally as here, a speed boost of about 67%.

To wring the most performance out of a regular SATA SSD on a Mac Pro, install the Accelsior E2 PCIe SSD, and use its eSATA ports for external SSDs, avoiding the internal Mac Pro SATA ports.

The external solution: install the SATA SSD into the OWC Mercury Elite Pro Mini USB3/eSATA case. In so doing, one gets the best of both worlds: much higher speed than the internal ports, but also the capability to use the same drive on another Mac, including one with USB3.

The write speed downward spike at end is normal for all drives as the file system approaches capacity, reads are unaffected.

Click for a larger graph.

OWC Mercury Accelsior E2 PCIe eSATA using external 6G SSD

Accelsior E2: eSATA vs internal SATA hard drive performance

The same Seagate 3TB hard drive was used; it is a very fast hard drive, but has somewhat spiky read performance on both the internal Mac Pro port (green lines) and the eSATA port (blue lines), though it was a little more variable via eSATA.

eSATA write performance (orange) was identical to Mac Pro internal SATA port write speed (red).

Click for a larger graph.

OWC Mercury Accelsior E2 PCIe eSATA versus Mac Pro internal SATA performance with Seagate 3TB hard drive