OWC Mercury Extreme Pro 6G SSD Review (120GB)

TRIM Performance

In practice, SandForce based drives running a desktop workload do very well and typically boast an average write amplification below 1 (more writes to the device than actual writes to NAND). My personal SF-1200 drive had a write amplification of around 0.6 after several months of use. However if subjected to a workload composed entirely of incompressible writes (e.g. tons of compressed images, videos and music) you can back the controller into a corner.

To simulate this I filled the drive with incompressible data, ran a 4KB (100% LBA space, QD32) random write test with incompressible data for 20 minutes, and then ran AS-SSD (another incompressible data test) to see how low performance could get:

You'll notice that the After Torture number is better than the 120GB Vertex 3. Remember that the OWC drive's 4KB random write performance is capped, so the drive simply doesn't get as fragmented in 20 minutes as the Vertex 3 - the behavior of the two drives would be the same if we wrote the same physical amount of data to each drive. Neither drive is quite as resilient as the 240GB version. If you are using your SSD primarily for incompressible data (images/videos/music) storage and manipulation then you're probably better off with an Intel SSD 510 or Crucial m4.

Power Consumption

Power consumption is a bit higher on the OWC drive than the Vertex 3, perhaps the firmware differences extend beyond just 4KB random write performance:

Final Words

With the exception of the (temporary?) 4KB random write cap and slightly higher power consumption, OWC's Mercury Extreme Pro 6G is a dead ringer for OCZ's Vertex 3 - at least at the 120GB capacity. The two come with comparable warranties which brings the decision down to pricing, where OCZ currently has a $20 advantage.

That's about as open and shut as you can get. My preference is still 240GB for anything SF-2200 based given the sizable increase in performance, but that added performance and capacity does come at a high price. Speaking of which, OCZ's retail 240GB Vertex 3 is next on my hit list...