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Crucial M225 256GB solid state drive (SSD)

Last updated 2009-09-10 - Send Feedback
Related: SSD, storage

Please see the extensive review of the Crucial 128GB solid state drive (SSD).

Performance can be expected to be nearly identical between the Crucial 256GB and 128GB models, with the 256GB model having a small but measurable speed advantage. It’s rated by Crucial for slightly higher performance of 200MB/sec versus 190MBe/sec for the 128GB model, but neither model actually can sustain that claim.

With 256GB capacity at slightly less than twice the price the Crucial 128GB offering, the 256GB model could be a swap-in replacement on many users systems, especially for laptop users.

The Crucial 256GB model is available for around $645 (street). View prices on SSD

Formatted capacity

Crucial 256GB SSD

A 256GB drive formats to about 238GB (where GB = 1024 X 1024 X 1024). Avoid using all that space— internal fragmentation on an SSD is an issue.

Appropriate uses

Until proven otherwise, use of an MLC-based drive like the Crucial, X25-M, etc is inappropriate for intensive writes eg a Photoshop scratch volume, unless one plans to regularly recondition the drive.

Performance — new and “seasoned”

Read and write speed is awesomely fast. But there is a hitch: the speed out of the box is a fairy tale that does not hold up with sustained use, although the ongoing speed is still superb.

The speed is actually understated when the drive is first used; fresh out of the box, the Crucial 256GB achieves a blistering-fast 215MB/sec write speed, and 267MB/sec read speed on the DiskTester fill-volume test. Those are fantastic numbers! (The fastest laptop hard drives might sustain 98MB/sec on the fastest part of the drive).

On the second and subsequent fill-volume tests, write speed declines by 17% over the initial results, settling down to a still superb 187MB/sec, about 6% below the rated speed. Furthermore, it develops a periodic stutter, which can be seen in the blue line in the graph. Read speeds drop only a smidgen, remaining above 260MB/sec.

There is no real-world issue here except the marketing claim that the Crucial 256GB can sustain 200MB/sec writes. That is simply not true once the unit has been (lightly) “seasoned”.

The graph below captures the results (click to view a large version).

  • the red line is the initial fill-volume;
  • the two nearly-identical blue lines are two subsequent fill-volume tests;
  • the three upper lines are the three passes (done after the writing of 1000 files of fill-volume).

I’m very pleased with this performance, I just don’t think that Crucial should claim 200MB/sec when only 187MB/sec can be achieved after the drive is “seasoned”. Furthermore, the fill-volume test is “friendly” in that it writes 32MB at a time; real-world usage tends to cause much more internal fragmentation.

MB/sec filling the entire drive capacity


Conclusions and recommendations

The Crucial M225 256GB solid state drive looks like an excellent choice. It offers blisteringly-fast performance that should liven up any system.

Laptop users in particular might find the capacity and speed extremely appealing. The speed simply cannot be matched by any hard drive configuration on a MacBook Pro, not even a dual eSATA configuration.

The only caveat (as with all SSDs) is that intensive write use can degrade speed over time, due to internal fragmentation, which might require a reconditioning effort every few months.

View prices on SSD

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