Review: OWC Mercury Extreme Pro 6g

A RAID-Ready Solid State Drive for Your Mac

OWC Mercury Extreme Pro RE SSD
OWC Mercury Extreme Pro RE SSD. Courtesy of Other World Computing

OWC's Mercury Extreme Pro RE SSD is the fastest SSD (Solid State Drive) I've ever installed and used on my Mac. I haven't been a fan of SSDs in the past. Sure, they deliver pretty good performance, but at a high price tag. In addition, their ability to maintain performance over their expected lifetime has been less than impressive.

OWC's Mercury Extreme Pro RE SSDs have completely turned me around.

While the price is still a bit high, their performance, reliability, and utter lack of performance degradation over time make me want to add SSD storage to my next Mac.

Update: The Mercury Pro RE SSDs are no longer available from OWC having been replaced by the Mercury Extreme Pro 6G which offer RAID support, a faster interface, faster data transfers up to 559 MB/s peak read, and 527 MB/s peak write, and a lower price.

The review of the OWC Mercury Extreme Pro RE SSD continues:

OWC Mercury Extreme Pro RE SSD - Specifications and Features

The OWC Mercury Extreme Pro RE SSD is a 2.5-inch SSD available in four sizes.

  • 50 GB Mercury Extreme Pro RE SSD
  • 100 GB Mercury Extreme Pro RE SSD
  • 200 GB Mercury Extreme Pro RE SSD
  • 400 GB Mercury Extreme Pro RE SSD
  • Controller: SandForce Processor SF1200 series with 28% over-provisioning
  • Full RAID support
  • Sustained sequential read: Up to 285 MB/s
  • Sustained sequential write: Up to 275 MB/s

The Mercury Extreme Pro RE SSD uses SandForce SF-1200 SSD processors, which were designed to maximize performance and power utilization, and create solid state drives that maintain their performance levels over the device's entire lifetime.

The tendency for write or read speeds to decrease over the lifetime of the device has long been an issue with SSDs. When you first install an SSD, you get pretty impressive performance, but over time, the speeds fall remarkably. This has been my main issue with SSDs: paying a premium price for technology that fizzles over time.

The SandForce controller in the Mercury Extreme Pro RE SSD uses some interesting technology to ensure that the performance of the SSD doesn't degrade over its expected lifetime, including:

  • Intelligent block management and wear leveling
  • Intelligent free space management
  • RAISE (Redundant Array of Independent Silicon Elements)
  • ECC data protection
  • Power/Performance balancing

OWC Mercury Extreme Pro RE SSD: Installation

The OWC Mercury Extreme Pro RE SSD is a 2.5-inch drive, the same size used in many notebooks. As a result, this SSD is a great fit as a replacement drive in any of the Apple MacBooks, MacBook Pros, and Mac minis. It can also be used in iMacs and Mac Pros, but an adapter may be required.

In my case I chose to install the SSD in my Mac Pro. I knew I would need an adapter to mount the 2.5-inch drive in the Mac Pro's drive sled, which was designed for a 3.5-inch drive.

Luckily, the adapters are inexpensive. OWC provided an Icy Dock screw-less 2.5-inch to 3.5-inch adapter that I could use for my testing. Please note: The Icy Dock isn't included with the Mercury Extreme Pro RE SSD, but is available as an option.

The Mercury Extreme Pro RE SSD easily snapped into the Icy Dock adapter. Once installed in the adapter, the SSD can be treated just like any other 3.5-inch hard drive. I quickly installed the SSD/Icy Dock combo onto one of my Mac Pro's drive sleds and was ready to start testing.

When I turned on the Mac Pro, OS X recognized the SSD as an unformatted drive.

I used Disk Utilities to format the SSD as Mac OS Extended (Journaled).

OWC provided the 50 GB model of the Mercury Extreme Pro RE SSD for testing. Disk Utility reported the initial drive capacity as 50.02 GB; after formatting, 49.68 GB was available for use.

OWC Mercury Extreme Pro RE SSD - How I Tested the Drive

Testing the OWC Mercury Extreme Pro RE SSD consisted of benchmarks, using Intech's SpeedTools Utilities to measure the SSD's read/write performance, and real-world testing, including measuring boot time and application launches.

I took read/write benchmarks after the drive's initial formatting. These benchmarks indicate the raw performance potential of the SSD. I broke the base benchmark test into three tests, using different file sizes to represent typical types of activities typical users would be involved in.

Once the initial benchmark testing was complete, I installed Snow Leopard (OS X 10.6.3) on the SSD. I also installed a selection of applications, including Adobe InDesign CS5, Illustrator CS5, Photoshop CS5, Dreamweaver CS5, and Microsoft Office 2008.

I then shut down the Mac and performed boot time tests, measuring the elapsed time from pressing the Mac Pro's power on button until the desktop first appeared. Next, I measured the launch times of individual applications.

I performed the final tests after seasoning the SSD by randomly writing and reading a 4K file 50,000 times. Once the drive was seasoned, I redid the basic read/write benchmarks to see if there was any falloff in performance.

OWC Mercury Extreme Pro RE SSD - Read/Write Performance

The read/write performance test consisted of three individual tests. I performed each test 5 times, then averaged the results for a final score.

Standard: Measures both random and sequential read/write performance on small files. The test files ranged from 4 KB to 1024 KB. These are typical file sizes seen in routine use, as a boot drive, email, web browsing, etc.

Large: Measures sequential access speeds for larger file types, from 2 MB to 10 MB. These are typical file sizes for consumer applications working with images, audio, and other multimedia data.

Expanded: Measures sequential access speeds for very large files, from 20 MB to 100 MB. These large files are also a good example of multimedia usage, though the larger sizes are more often seen in professional applications, large image manipulation, video work, etc.

Read/Write Performance
 Standard (MB/s)Large (MB/s)Expanded (MB/s)
Peak Sequential Read247.054267.932268.043
Peak Sequential Write248.502261.322259.489
Average Sequential Read152.673264.985267.546
Average Sequential Write171.916259.481258.463
Peak Random Read246.795n/an/a
Peak Random Write246.286n/an/a
Average Random Read144.357n/an/a
Average Random Write171.072n/an/a

OWC Mercury Extreme Pro RE SSD - Boot Up Test

After the initial read/write test of the OWC Mercury Extreme Pro RE SSD, I installed Snow Leopard and a mix of applications to test launch times. While I didn't measure the process, the installation of Snow Leopard and the three Adobe CS5 products seemed to go quickly. Usually when I'm installing any of these products, I expect to spend a fair amount of time waiting for the process to finish.

Of course, the initial read/write tests I performed should have clued me into the raw performance potential of this SSD, but actually experiencing the performance, rather than simply measuring it, is quite a kick.

I performed the boot test with a stopwatch, to measure the elapsed time from pressing the Mac Pro's power on button until the desktop first appeared. I performed this test 5 times, always from a power off state, and averaged the results for a final score.

For comparison, I measured the boot time of my usual startup drive, a Samsung F3 HD103SJ. The Samsung is a better-than-average performer, but by no means one of the fastest platter-based hard drives available.

Mac Pro Boot Time

  • Samsung F3: 51.8 seconds
  • OWC Mercury Extreme Pro RE SSD: 30.7 seconds

The difference in boot times was impressive. I hadn't thought of my current startup drive as contributing to a slow boot process, but after experiencing the faster SSD drive, I've seen the light.

OWC Mercury Extreme Pro RE SSD - Application Launch Test

Application launch times may not be the most important attribute to test. After all, most individuals launch their workhorse applications only once or twice a day. How much does shaving a little off of this time contribute to overall productivity?

The answer is probably not a lot, but it does serve an important function. It provides a measurement that can be easily referenced against day-to-day Mac usage. Measuring read/write speeds provides raw performance numbers, but measuring application launch times puts the performance in perspective.

For the application launch test, I chose 6 applications that should represent a good cross-section for Mac users: Microsoft Word and Excel 2008, Adobe InDesign, Illustrator, and Photoshop CS5, and Apple Safari.

I performed each test 5 times, restarting the Mac Pro after each test to ensure that no application data was being cached. I measured the launch times for Photoshop and Illustrator from when I double-clicked an image document associated with each application until the application opened and displayed the selected image. I measured the other applications in the test from when I clicked their icons in the Dock until they displayed a blank document.

Application Launch Times (all times in seconds)
 Mercury Extreme Pro RE SSDSamsung F3 Hard Drive
Adobe Illustrator4.311.5
Adobe InDesign38.9
Adobe Photoshop4.98.1

OWC Mercury Extreme Pro RE SSD - Final Benchmark

After I finished all of the previous tests, I once again ran the read/write performance benchmark. The purpose of running the benchmark a second time was to see if I could detect any performance falloff.

Many currently available SSDs have a nasty habit of declining in performance after only a bit of use. To test how well the OWC Mercury Extreme Pro RE SSD will perform over time, I used it as my daily startup drive for two weeks. During those two weeks I used the drive for all of my typical tasks: reading and writing email, browsing the web, editing images, playing music, and testing products. I also watched a few movies and TV shows, just for testing purposes, you understand.

When I finally got around to running the benchmark tests again, I saw very little difference. In fact, all of the differences could be explained by simple averaging errors in my samples.

Final Benchmark (all times in MB/s)
Peak Sequential Read250.132268.315269.849
Peak Sequential Write248.286261.313258.438
Average Sequential Read153.537266.468268.868
Average Sequential Write172.117257.943257.575
Peak Random Read246.761n/an/a
Peak Random Write244.344n/an/a
Average Random Read145.463n/an/a
Average Random Write171.733n/an/a

OWC Mercury Extreme Pro RE SSD - Final Thoughts

The OWC Mercury Extreme Pro RE SSD was impressive, in both its initial performance and its ability to maintain performance levels over the time I had the drive for testing.

Much of the credit for the performance of this SSD goes to the Sanford processor, and the over-provisioning of the SSD by 28 percent. In essence, the 50 GB model we tested actually has 64 GB of available storage. Likewise, the 100 GB model contains 128 GB; the 200 GB model has 256 GB; and the 400 GB has 512 GB.

The processor uses the extra space to provide redundancy, error correction, wear leveling, block management, and free space management, all methods to ensure the same level of performance over the anticipated 5-year lifetime.

The raw speed is impressive, well beyond what you'd expect to see in standard platter-based hard drives. After using the OWC Mercury Extreme Pro RE SSD for two weeks as a loaner, I'm sorry to send it back.

If you're looking to optimize your Mac's performance, this series of SSDs from OWC should be on your short list. The smaller models would be very effective as scratch space for multimedia authoring or image editing applications. The larger models would make fantastic startup drives if you want maximum performance, all the time.

The only downside to the OWC Mercury Extreme Pro RE SSDs is their price. Like all SSDs, they're still at the upper end of the price/performance equation. But if you have a specific need for speed, you won't go wrong with these drives.