Intel made a lot of noise when it arrived on the SSD market in September 2008. With an ultra-high performance 10 channel controller, very effective wear levelling and limitation of writes on memory blocks, the Santa Clara giant had come out with an SSD with as yet unseen performance and out of the ordinary reliability with 100 GB/day writes for 5 years on MLC drives.
Unfortunately our enthusiasm was chilled due to a problem with stability of performance that showed itself in our first tests of the drive. After speaking of “expected behaviour”, Intel did correct the problem with a new firmware in April in response to criticism from tech media on the other side of the Atlantic.
With this problem resolved, the X25-M was once again an intriguing proposition though in terms of price per GB somewhat behind the recent competition from manufacturers using the Indilinx Barefoot controller (OCZ Vertex, GSkill Falcon, SuperTalent UltraDrive ME, Crucial M225, Corsair Extreme …) or Samsung S3C29RBB (Samsung PB22-J, OCZ Summit, Corsair Performance …). Initially planned for the last quarter of the year, the new X25-M is anticipated with a great deal of interest.
34 nm Flash chips
To start with, here’s how to distinguish the previous X25-Ms from these new ones, code name Postville :
- Old: SSDSA2MH080G1
01 and SSDSA2MH160G1
- New: SSDSA2MH080G2
C1 and SSDSA2MH160G2
The main difference between these two revisions lies in the type of MCL NAND Flash used. Micron, Intel’s partner for everything Flash, is still the supplier but while the chips were previously manufactured at 50 nm, they now the new 34 nm process. This brings two advantages: the cost per GB is lower because of higher density, and the chips give better performance.
The old 160 GB X25-M used twenty 8 GB chips, while the new one uses 10 16 GB chips, which leaves the door open for a 320 GB version. This Flash memory is faster, Intel announcing read latencies at 65µs instead of 85µs and write latencies of 85µs instead of 115µs. In practice random reads of 4 KB blocks remains identical at 35000 IOPS, while for random writes of the same size we are up from 3300 to 6600 (80 GB) and 8600 (160 GB) IOPS. Sequential speeds are identical with reads at 250 MB/s and writes at 70 MB/s.
When you open the SSD you discover another difference: the memory cache is up from 16 to 32 MB. While previously Samsung SDRAM was used, now you’ll find it’s a Micron chip.
To give you an idea of the reduction in price over the last 10 months, you should know that the first X25-Ms were on sale for $595 and $945 for the 80 GB and 160 GB versions respectively. The new X25-Ms are at $225 and $440, a cut of 62% and 53%! Compared to the most recent prices for the X25-M V1s, the V2s are between 25% and 30% cheaper.