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Upgrade Advice: Does Your Fast SSD Really Need SATA 6Gb/s?

Benchmark Results: 128 KB Sequential Performance

Sequential Read Performance

Examples include file copying, transcoding, game level loading, some gameplay, watching video, and editing video

In sequential reads, every drive attached to SATA 3 Gb/s offers performance between 200-300 MB/s. In this discipline, Intel's mainstream SSD 320 is on par with the high-end 6 Gb/s drives as a consequence of the ceiling imposed by second-gen SATA.

Uncorking the platform to enable 6 Gb/s data rates allows the m4, 830, and Vertex 3 to shoot up between 350-550 MB/s. Naturally, the SSD 320 doesn't see any speed-up because it's a 3 Gb/s drive.

Compressible Sequential Write Performance

When it comes to dealing with compressible data, SandForce-based SSDs enjoy a particular advantage, since the company’s architecture employs compression to achieve breakneck speeds. That explains why the 240 GB Vertex 3 wins so definitively in this test, serving as the only drive able to break through 500 MB/s.

Samsung's 256 GB 830 finishes in second with a sequential write rate around 400 MB/s, but only at queue depths higher than two. Just bear in mind that the two drives only achieve those numbers attached to SATA 6Gb/s.

If you're stuck using SATA 3Gb/s, it's more difficult to pick a winner because all of the drives are capped between 180-280 MB/s. Interestingly, Crucial's m4 is the highest performance at a queue depth of one in a 6 Gb/s configuration. But once you scale up to higher outstanding commands, you see no difference between a newer system capable of SATA 6Gb/s and one still leveraging SATA 3Gb/s.