[Brian]

The OWC Mercury Extreme Pro series of SSDs leverage the SandForce SF-1200 controller and are firmly entrenched in the performance SSD category. Aside from blazing 285MB/s read speeds in capacities up to 480GB, the Mercury Extreme Pro features a nifty all-metal blue-painted case and a claim of reduced power consumption (compared to other leading SSDs) that's sure to excite notebook users.

OWC is one of the few SSD manufacturers who offers transparency when it comes to the portion of the drive used for wear leveling, in this case, about 7%. Our 120GB review drive for instance uses about 8GB for these processes, leaving just under 112GB available to the end-user.

What really counts though in this class of SSD is performance. And while the details follow below, it's hard to resist throwing out this little spoiler - the OWC Mercury Extreme Pro is the fastest SATA II SSD to hit our test bench yet. Read on to see how the OWC stacks up against the best in class SSDs in both synthetic and our exclusive real world benchmarks.

Full Review

[udaman]

Brian, on 09 August 2010 - 01:29 PM, said:

OWC is one of the few SSD manufacturers who offers transparency when it comes to the portion of the drive used for wear leveling, in this case, about 7%. Our 120GB review drive for instance uses about 8GB for these processes, leaving just under 112GB available to the end-user.


Full Review

^from link above:

Quote

Over Provisioning & Wear Management Explained
Some of the drive space in OWC SSDs are allocated for RAISE – which provides real time data redundancy, ECC Error Correction, and reserve cell space.
Example: An OWC Pro SSD that's 240GB in size with 7% over-provisioning is actually a 256GB drive with 7% allocated for data management, and to maintain the drive's high-performance level.
Unlike most SSDs on the market today, the Mercury Pro family uses advanced DuraWrite™ wear-leveling and block management technologies to keep Read/Write performance at peak while others see performance fall.

^...isn't that implying a 128GB drive, with 7% over-provisioning is then a 120GB drive... ie. the 8GB difference btw 128GB & 120GB is the portion used for over-provisioning?

And that your final formatted number is what is then the real available storage space (which may vary a bit from one OS to another, depending on how the drive is formatted/file format system used?) < independent of the 7% over-provisioning allocation?

Just sounds confusing the way you worded it

[TSullivan]

Well it depends what you are looking at. The drop in capacity from formatting, provisioning, or the 1000 byte vs 1024 byte argument.

[boli]

I'm with udaman. The drive contains 128 GB of flash, of which 120 GB is "exposed". The RE edition has the same amount of flash, but exposes only 100 GB to the computer.

Quote

120GB Capacity (111.79GB Formatted)

That your OS displays a capacity of 111.79 GB has nothing to do with formatting, and everything with decimal vs binary multiples (your OS should say either 111.79 GiB or 120 GB). As a storage site you must be aware of this, and I'd certainly appreciate if you'd make use of the knowledge in your reviews, in order to educate the readers. Suggesting that ~8 GB is somehow lost due to formatting is misleading at best.

This post has been edited by boli: 10 August 2010 - 01:02 PM

[TSullivan]

The quick formatted stat isn't included to explain the drop after formatting, instead it was prompted by a request in this post where the end user found that two drives with the same listed capacity were unequal when formatted:

http://forums.storag...atted-capacity/

Its an all-inclusive number we give since it is readily available from the reviewing process and doesn't rely on information from the manufacturer on provisioning or wear leveling reserved sections. We include outside data (in this case OWC was open in terms of what the space is used for) but in most simple terms its just a figure of how much space is available on the drive for the user without getting into arguments of where it went.

Now as we fill out our glossary section this topic can be outlined to discuss the areas space "disappears to" when the manufacturers claim capacity, but for now we just wanted to add on the formatted capacity to reviews to help out people who just want to know how much space the drive has.

[boli]

Fair enough, I appreciate you posting the capacity available to the end user. I just wish you'd call it GiB rather GB. You know, my OS * displays a capacity of 200.05 GB for my OWC SSD, so if I read "formatted capacity 186 GB" I'd scratch my head. Or rather I'd think the reviewers don't know the difference between GB and GiB.

And in this particular review you make it sound as if the difference between the nominal capacity (120 GB) and the formatted capacity (~112 GiB) is due to over-provisioning, which is not the case.

* Mac OS X 10.6.x. Also I think some Linux distributions display GiB when they mean GiB, unlike Mac OS < 10.6 or any Windows.

This post has been edited by boli: 11 August 2010 - 12:41 PM

[nrpardee]

I'm looking at this review and the earlier April 2010 review of the Intel X25-M. The numbers for the X25-M are different, and I'm wondering if that reflects a different rev of the model, different test techniques, updated testing software, different hardware, or ????

Thanks for the reviews.