Conclusion

Ten-channel architecture of the controller’s interaction with flash memory chips, a good processor with effective algorithms, and buffer memory have been combined by Intel to produce the high-performance storage X25-M. Our bravos go to the developer who has managed to transform the ugly duckling of early SSDs into a swan. We must also keep it in mind that the X25-M employs multi-level-cell memory which is considerably cheaper than single-level-cell chips, being inferior to the latter in write speed and service life.

The speed characteristics of this 2.5-inch SSD are so superb that it will easily outperform RAID0 arrays built out of multiple disks, which is one of the very few available methods of boosting your disk subsystem performance. And the SSD needs less power and takes less space than a RAID. It seems that RAID arrays (except for those comprising lots of disks) will soon be relegated into the sector of redundant data storage or will be used when high speed must combine with high capacity.

A hard disk drive has but few advantages left over a solid-state drive: low cost of storage, high storage capacities, and somewhat higher speed of writing (as yet). The latter advantage may vanish quite soon because the upcoming SLC-based X25-E series is declared to deliver a write speed of 170MBps. HDDs with such a high write speed are not expected any time soon.

The SSD is yet behind the HDD in terms of capacities, even though the gap is getting smaller. The capacity of the SSD we have tested today is 80 gigabytes and Intel plans to introduce a 160GB model in Q4 of this year, but 2.5-inch hard disk drives of all the manufacturers have already reached a capacity of 320GB and are approaching 500GB. 3.5-inch HDDs are going to step from the 1TB milestone even further.

Well, the capacity is closely linked to the price factor. And it is from this aspect that SSDs are far inferior to HDDs. High speeds and low access time come at a high price. It is technically easy to increase the capacity of an SSD by using a bigger case and more memory chips, but the resulting device would be far too expensive. The 80GB X25-M comes at a price of $595. So, the price of each gigabyte of its storage space is about $7.5 whereas the price of one gigabyte of hard disk storage is far less than 1 dollar. On the other hand, SSDs have progressed in terms of pricing, too. The manufacturers obviously have some elbowroom determined by the manufacturing cost of the chips. We just have to wait for a real price war and reap the results.

So far, we can see a clear picture: rather small but very fast SSDs are going to be used in applications that require high performance of the disk subsystem whereas HDDs will be used for storing the bulk of data and will work as the main storage only when high speeds are not necessary.

There is only one thing we could not check out practically in our tests. And unknown as it is, this factor is the most alarming one. How long will the service life of an SSD be? How long will the X25-M work in an expensive notebook, a high-performance workstation or a server? How soon will those 10,000 rewrite operations guaranteed for modern MLC memory expire in practical applications, even considering the wear-leveling algorithms? How long will an SLC-based model with its guaranteed 100,000 rewrites work in a highly loaded server with lots of writes? These questions surely need more investigation.

Anyway, we’d like to end this review with a positive note. The Intel X25-M boasts such a quick access time that it is just incomparable to HDDs and many previous SSDs. It also delivers superb performance at random-address operations (at both reading and writing), a very high speed of sequential reading and a sufficiently high speed of sequential writing. It is a new star in the high-performance storage world. And we promise you to keep our eye on it.