[REQUEST] Allow UDMA 100 on ThinkPad R40 with mSATA SSD

[ibrazhko]

Hello!

I would like to request a BIOS modification to allow my ThinkPad R40 (from 2002!) to operate the drive at UDMA 100 speeds. UDMA 100 is supported by both the motherboard and the drive (I upgraded to mSATA SSD via adapter), but unfortunately, the BIOS limits it to UDMA 33 speeds only.

Normally, during power-on computers check whether HDD is connected with a 40-pin or 80-pin cable, because 80-pin cable is capable of UDMA speeds higher than 33. This is done by checking if pin #34 is grounded - if it is, it understands that 80-pin cable is being used and enables speeds higher than UDMA 33. But this is not the case for some ThinkPads of that era, including R40. Instead of performing this hardware check, it performs a software check - it just reads what the drive reports, specifically in IDENTIFY DEVICE Word 93. Because my drive is mSATA (and not PATA), it automatically reports IDENTIFY DEVICE Word 93 as zero, and so ThinkPad's firmware configures PATA controller to report '80 conductor cable not detected'.

Link to BIOS: http://download.lenovo.com/ibmdl/pub/pc/...uj24us.exe

This machine is very dear to me, so I would MUCH appreciate if you could change this in the BIOS. Perhaps, hard-set it to UDMA 100 or make a BIOS setting to switch between UDMA 33/100 speeds would do the trick.

Thanks so much in advance!