Maximum PC Staff Aug 11, 2009

Samsung 256GB MLC SSD

At A Glance


Blistering read and write speeds, high capacity (for an SSD).


Expensive (natch). Occasional high latency, but nowhere near as bad as other controllers.

Expensive, but worth it

[ Editor's Note: This drive retails as the Corsair P256 . At the time this review was first published, Samsung had announced no retail partners.]

Solid state drives show immense promise with regards to reliability and read speeds, but current-generation models are rife with drawbacks. Due to NAND flash memory’s architecture, writing data to a block (after the first time) requires copying the entire contents of that block to cache, erasing it, and rewriting it with the added data. Large numbers of small writes run the risk of overloading the SSD’s disk cache, causing high latency. Multi Layer Cell (MLC) solid state drives, especially those utilizing JMicron’s JM602 controller, are particularly susceptible.

Fortunately, Samsung’s SSDs, like Intel’s (whose X25-M is the gold standard for solid state drives), use their own controllers, and the results are impressive. This 256GB SSD reached sustained average read speeds of 175MB/s, just 12 percent slower than the Intel drive and 75 percent faster than a Western Digital VelociRaptor. Better still, the Samsung drive’s average sustained write speeds topped 150MB/s, much faster than the 64.3MB/s average offered by the Intel drive. Oddly, Intel’s X25-M still reigns supreme in our Premiere Pro encoding test, beating the Samsung drive by nearly two minutes. The Samsung’s random access times, while slightly slower than the X25-M’s, still average at under .2ms for read and write.

The Samsung drive’s PCMark Vantage score, at 14,088, is less than half that of the Intel drive’s, but still double that of any standard hard drive.

Samsung's new 256GB SSD crushes the competition in capacity and write speeds.

Now to that pesky random-write latency issue that vexes SSDs: The Samsung controller hung up only a few times, once giving a random-access write latency of 294.5ms, which is enough for a noticeable lag. However, this occurred infrequently enough that the average random-access write latency was .16ms, several thousand times faster than the CSX 128GB SSD, for example, which used the flawed JMicron controller.

The Samsung 256GB SSD, then, exhibits blazing-fast read speeds, and its write speeds are not just fast but consistently fast, at an average of 150MB/s, which is a nice change from the status quo. Even better, this SSD has a high enough capacity to run both the OS and applications (like games and media-creation apps) that can benefit from its high read and write speeds and low latency.

Samsung doesn’t currently plan to offer the 256GB MLC SSD through normal retail channels, but the Corsair P256 SSD, which features the same hardware, is available on NewEgg and other retailers, and the Samsung OEM version is available as an add-in in some Dell and Alienware computers. Its read speeds are nearly on par with the X-25M, its writes are much faster, and it has three times the capacity. If you’ve got the scratch, this is one of the few SSDs currently out that we can unreservedly recommend.

Editor's Note : Added language indicating Corsair P256 as rebranded version of this drive.


Samsung 256GB MLC SSD
Intel X25-M
Western Digital VelociRaptor
256GB 80GB
Average Sustained Transfer Rate Read (MB/s) 175.1
Average Sustained Transfer Rate Write (MB/s) 150.1


Random Access Read (ms)
Random Access Write
Premiere Pro (sec) 945
PCMark Vantage Overall Score
6, 082
Best scores are bolded. All drives were tested on our standard test bed using a 2.66GHz Intel Core 2 Quad Q6700, EVGA 680i SLI board. HDTach, h2benchw, and Premiere Pro CS3 were obtained in Windows XP; PCMark Vantage 2005 scores were obtained in Windows Vista Home Premium 32-bit.

Samsung 256GB MLC SSD

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