OWC Mercury Extreme Pro 6G 4TB SATA SSD Review

With SATA SSDs now almost exclusively delegated to secondary drives, capacity is left pushing this aging tech forward. Recently, OWC announced an additional jump in capacity to 4TB for their top tier Mercury Extreme Pro 6G. With the 2TB model recently reviewed, it's time to see how the additional 2TB of capacity affects performance.

As mentioned when we had the 2TB model in house, the Extreme Pro 6G welcomed a controller change to the Phison S12 in revision 2, and this 4TB takes on its own hardware design as it deploys the Phison S12DC variant for this model alone.

On paper, performance is unchanged the 4TB model offering 550 MB/s read and 530 MB/s write for sequentials and 100K IOPS for random read and write. Additional features include 7% over-provisioning with 128GB allocated to real-time data redundancy and EC. We have a usable capacity of 3968GB and support for NCQ.

The MSRP of the 4TB Mercury Extreme Pro 6G comes in at $899.99 with a five-year warranty.

Once again, we meet back at the cardboard retainer familiar to all OWC 2.5" solutions. Capacity listed top right at 4TB.

Included with the drive is a z-height spacer to push the drive to 9mm for notebooks.

The bottom of the drive offers model identification along with capacity and regulatory information.

A few screws hold the drive shell together.

Taking a look at the hardware, we have the Phison S12DC to the right with four DRAM packages, two on this side. Eight NAND packages take up much of the real estate next to blank solder pads, where we would normally find capacitors for power loss prevention.

Flipping the drive, we have the last two DRAM packages at the top with another eight NAND packages.

CDM is a staple in performance testing; version 7 has seen some updates in the workloads used for testing. Sequential performance tops out at 559 MB/s read and 514 MB/s write with 43 MB/s read and 108 MB/s write for 4KQ1.

ATTO is yet another popular benchmark for storage performance that breaks down performance based on file size. The Extreme Pro 6G is very consistent in this scenario 256K through 64M holding 534 MB/s read and 492 MB/s write.

PCMark10 switches things up with the Extreme Pro 6G coming in just behind the Barracuda SSD in quick system drive.

Full System Drive shows quite well for the 4TB Extreme Pro 6G as well, scoring 960.

Price/Performance landed the drive just above the BX500 from Crucial at 97%.

With testing out of the way, the 4TB variant of the Mercury Extreme Pro 6G has outstanding build quality backed by the datacenter version of the Phison S12 controller. OWC did save by omitting the power caps, but with the DC firmware in place, it does still get the benefits.

In our testing, the performance of the Mercury Pro 6G was top-notch, reaching 559 MB/s read and 514 MB/s write on par with top tier SATA solutions on the market. 4KQ1 was also rather good at 43 MB/s read and 108 MB/s write. Moving into PCMark10 testing, the Extreme Pro 6G did rather good ending up third in both the Quick and Full System drive charts.

Price is a bit of a concern with the 4TB variant of the Extreme Pro 6G as its current MSRP of $899.99 is almost double of competing solutions like the 860 EVO, 860 QVO, and WD Blue.

Tyler's Test System Specifications

• Motherboard: ASUS Crosshair VIII Formula X570 (buy from Amazon)
• CPU: AMD Ryzen 5 3600 (buy from Amazon)
• RAM: Corsair Vengeance 16GB 2x8GB DDR4 3600 (buy from Amazon)
• Cooler: Corsair Hydro H60 (buy from Amazon)
• Case: Corsair Carbide 275R (buy from Amazon)
• OS Storage: Corsair MP600 1TB (buy from Amazon)
• Power Supply: Corsair RM850x (buy from Amazon)
• OS: Microsoft Windows 10 (buy from Amazon)