1,5 years later, I want to connect to this bug, rather than adding a new bug, that I see inconsistent behavior on SATA III in my setup with kernel 3.16 and on Trusty 14.04 LTS. I am running 3 256GB SSDs and a couple of old rotating rust SATA II on my desktop. The system runs on a Samsung 840 PRO with roughly 0.45 GB/s throughput on SATA Port 1. Two cheap Crucial MX100 run on SATA Ports 2 and 3. In about 50% of the cases (usually after a complete shutdown of the system WITHOUT disconnecting the board from mains) the MX100s get detected as SATA III. Very often, they don't. I have "raided" them with zfsonlinux, so they hold my 500 GB "fast, but expandable" 2-node pure ssd zpool (to be enlarged, should rotating rust die...). If SATA III has been enabled, the pool runs close to 1 GB/s read and 0.6 GB/s write. The 50%s of boots where SATA III has not been enabled for them, it's down to about half of that value (0.5 GB/s read / 0.4 GB/s write.
My suspicion: some parameters are too restrictive to allow SATA III link to be established reliably and depending on BIOS/EFI and maybe a race condition (?) SATA III is per-default not tried hard enough. I have yet to research any finetuning in /proc or wherever that might be related. (I record <dmesg | grep "up 3.0"> and <dmesg | grep "up 6.0" > to file >> satastate.txt and it is mixed all over boots, sometimes with and sometimes without SATA III. The Samsung does just fine and I did interchange and replace a lot of cables already..) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/889071 Title: SATA III recognized as SATA II (chipset intel z68) To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/889071/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
