I have 2 identical HDDs (1TB Seagates) and a DVDWriter in my system and all are connected using SATA 3 cables. I couldn't but help noticing last night that transferring data between a new external SATA 3 HDD I bought yesterday and one of my internal drives was at ~130 MB/s as agaist ~27 MB/s with the second drive. So I went looking in /var/log/messages. Sure enough the kernel had decided that the second HDD has a 40-wire cable and has therefore configured it to have UDMA 33! The devices are shown as: ata1 max UDMA 133 configured as 133 UDMA ata5 max UDMA 133 configured as 33 UDMA (because connected using 40-wire cable) ata3 max UDMA 100 configured as 100 UDMA (this is the DVD writer) This was also occurring on my other 32-bit system (different devices of course) and there I was able to overcome this nonsense by adding to the kernel boot parameters- libata.force=1:80c,2:80c but doing similar on the system (see signature line below) the kernel locks up when the system is booting. How the heck can the kernel get it so wrong re the cabling (I know that the SATA and ATA use the same controller) and treats the second HDD as a poor relative? Is the kernel designed to only always know about one single HDD? Does anyone know, please, what I need to add in the kernel boot parameters to get this second HDD running at full UDMA speed? BC -- Using openSUSE 12.2 x86_64 KDE 4.9.4 & kernel 3.6.8-1 on a system with- AMD FX 8-core 3.6/4.2GHz processor 16GB PC14900/1866MHz Quad Channel Corsair "Vengeance" RAM Gigabyte AMD3+ m/board; Gigabyte nVidia GTX550Ti 1GB DDR5 GPU -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-kernel+owner@opensuse.org