Thinkpad X40 DIY SSD

I recently got a Thinkpad X40 from IBM's certified used equipment and it's an absolutely gorgeous machine! In fact, I'm sitting in a local coffee shop right now having a lazy Saturday morning and writing this post on my new laptop.
I've always been tempted by the X-Series Thinkpads, because of their tiny, ultra-portable form factor. It's not quite like the MacBook Air, but pretty darn close (and Lenovo just announced the X300, which will be even more like the Air).

Tiny size comes at a price though. The biggest drawback that I've noticed with the X40 is the relatively slow hard drive. My original plan was to replace the 40GB 4200rpm HDD with a larger, faster drive. This plan, however, was thwarted when I found that the X40 doesn't use the standard 2.5" notebook hard drive, but rather a 1.8" Hitachi Travelstar.

In search for an alternate solution I came across this article about building a solid state drive using compact flash memory. This, of course, appealed deeply to the geek in me, and so I set out to research different options and whether they would fit into the 1.8" hdd bay. I found the Addonics IDE to CF adapter to be a suitable solution.

Addonics IDE-to-CF adapter

In contrast to the SATA-to-CF adapter used in the article above, IDE to CF is really simple, because compact flash already supports the ATA hard drive interface. The adapter is therefore much smaller, basically just matching the 44 pin laptop IDE interface to the compact flash pins. The Addonics adapter supports two compact flash cards, which show up as separate drives.

1.8" hard drive vs. compact flash SSD

In comparison with the 1.8" hard drive, the CF-SSD is less wide and about the same length and height and fits well into the X40.

Installed SSD (using one CF card)

I did not perform any extensive performance tests on the different configurations, but here are the write and read speeds for a 1GB file using dd.

Name	Write	Read
Hitachi HDD	1:18	2:08
4GB Transcend 45x CF	3:23	1:15
8GB Lexar 300x UDMA CD	0:58	0:32

Both CF solutions provide significantly better read performance. However, the 4GB Transcend 45x card tanks during writes. In contrast, the 8GB Lexar 300x UDMA card outperforms the other two solutions quite comfortably, but at a higher pricepoint (~$90 for the CF card instead of the common $40 for a low speed CF).

The do-it-yourself solid-state drive costs about half of the currently available SSD's (Samsung 32GB SSD is available for $650 vs. an estimated $380 for 32GB compact flash plus the adapter ($20)), but much less if you can live with less storage. Another concern with the DIY solution is the potential of burning out the compact flash memory, which usually supports only 100.000 read/write operations. It is therefore not really suited to run Windows, because paging cannot be turned off. I'm running Ubuntu Linux without swapping and will see how long the compact flash will make it.

Overall, it is pretty cool to have an SSD X40, but many compromises had to be made. The solution doesn't work with Windows and provides only 8GB of storage. What I would really like to see is an adapter that supports 8 or 16 SD cards with striping and wear leveling, which should provide much faster read/write speeds and take advantage of the low cost for small (2GB/4GB) SD cards (recently picked up a 2GB SD card for $5).