Changing SATA speed on HP Probook 6560b with Transcend SSD370

Question

I have an HP Probook 6560b with updated BIOS version F.60 Rev.A (31 Mar 2015) and a Transcend SSD370 256GB SATA 3 SSD. On that I run Debian 8.1 with grub2 (not grub-efi).

The default setting in BIOS for "Max SATA Speed" is 3.0 Gbps, which is the speed of SATA 2. Both my laptop and the drive supports SATA 3. However, when I change the maximum speed to 6.0 Gbps, I get all sorts of errors when trying to boot into Linux. Changing that setting back fixes the problem, allowing me to write this question on the same laptop.

Strangely, the error is different every time I try to boot. Sometimes it is something about video mode not found. Other times I get the grub-rescue> prompt.

How can this be fixed, so that both the laptop and the SSD use SATA III, without reinstalling my distro?

Solution

Unfortunately, your particular laptop model is notorious for being incompatible with SATA-III SSD's. There are at least a couple of threads about this problem on HP's support forum: this and this.

One owner claimed that he could get his SSD working with his 6560b after flashing the 8560p's F.20 BIOS, which is of course very risky.

So, you can either keep using the SSD in SATA-II mode, or take your chances with flashing the 8560p's BIOS.