Improved SSD performance on old Thinkpads with BIOS mod

Recently, my old harddisk produced some errors. As I care for my data, I immediately replaced it and decided to invest in an SSD.

My laptop (Lenovo Thinkpad T61) is already some years old, so I'm quite aware that I won't get the best possible performance out of it. But I found something really interesting. The BIOS seems to limit the SATA II speed and there's an unofficial BIOS mod to remove that limitation. It's also available for a couple of other Thinkpad models (beside T61 also for R61, X61, X300 and variants of them).

The BIOS mod also does a number of other things, for example the official BIOS has a whitelist of allowed wireless chips. That gets removed.

The full feature list from the readme file:
- Disabled whitelist check.
- Enabled SATA II full speed.
- Added SLIC 2.1 table.
- Removed "Thermal sensing error" boot message (Penryn CPUs).
- Added dual-IDA support.

Obivous Warning: You're doing this at your own risk. If any unofficial BIOS destroys your laptop or your data, that's bad luck. The only thing I can tell is that I didn't experience any problems and that so far, a lot of people seem to use these BIOS mods without problems.

Now I did some before-after-benchmarking. I used hdparm -tT /dev/sda and a simple dd if=/dev/zero of=/tmp/out.img bs=8k count=256k. I started the benchmark after a fresh boot without anything else running to avoid disturbances. I ran the tests a couple of times and will only give you the last result of each tests, but they didn't differ much. The results:

	before	after
hdparm cached read	3069.01 MB/s	6900.56 MB/s
hdparm buffered read	131.38 MB/s	251.79 MB/s
dd write	106 MB/s	209 MB/s

Quite impressive, isn't it? I just doubled the speed of my disk for free. I'm aware that benchmarking is a tricky business and the impact this has on my overall system performance is probably difficult to put in numbers, but the results are significant enough that I think it was worth it.

Slightly related: There's also a modified firmware for the Optiarc AD7910A CD/DVD burner that's shipped in my laptop.