Just to add some more anaylsis results to narrow this issue down: Removing "all_generic_ide" from grub, and enforcing use of sata_uli (over ahci) by explicitly adding sata_uli to /etc/modules (and calling "update-initramfs") did the trick for me:
$ sudo hdparm -tT /dev/sda /dev/sda: Timing cached reads: 1790 MB in 2.00 seconds = 895.06 MB/sec Timing buffered disk reads: 228 MB in 3.02 seconds = 75.39 MB/sec $ sudo hdparm -tT /dev/sdb /dev/sdb: Timing cached reads: 1892 MB in 2.00 seconds = 946.23 MB/sec Timing buffered disk reads: 226 MB in 3.01 seconds = 74.98 MB/sec dmesg extract: ... [ 16.715632] libata version 3.00 loaded. [ 16.716662] sata_uli 0000:00:12.1: version 1.3 [ 16.716674] ACPI: PCI Interrupt 0000:00:12.1[A] -> GSI 19 (level, low) -> IRQ 19 [ 16.716788] scsi0 : sata_uli [ 16.716841] scsi1 : sata_uli [ 16.716968] ata1: SATA max UDMA/133 cmd 0xec00 ctl 0xe080 bmdma 0xd880 irq 19 [ 16.716971] ata2: SATA max UDMA/133 cmd 0xe000 ctl 0xdc00 bmdma 0xd888 irq 19 [ 17.180710] ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300) [ 17.230594] ata1.00: ATA-7: ST3320620AS, 3.AAE, max UDMA/133 [ 17.230598] ata1.00: 625142448 sectors, multi 16: LBA48 NCQ (depth 0/32) [ 17.297117] ata1.00: configured for UDMA/133 [ 17.762934] ata2: SATA link up 1.5 Gbps (SStatus 113 SControl 300) [ 17.813154] ata2.00: ATA-7: ST3320620AS, 3.AAE, max UDMA/133 [ 17.813157] ata2.00: 625142448 sectors, multi 16: LBA48 NCQ (depth 0/32) [ 17.879691] ata2.00: configured for UDMA/133 [ 17.879868] scsi 0:0:0:0: Direct-Access ATA ST3320620AS 3.AA PQ: 0 ANSI: 5 [ 17.879991] scsi 1:0:0:0: Direct-Access ATA ST3320620AS 3.AA PQ: 0 ANSI: 5 ... [ 19.703935] ahci 0000:03:00.0: AHCI 0001.0000 32 slots 1 ports 3 Gbps 0x1 imp l SATA mode [ 19.703940] ahci 0000:03:00.0: flags: 64bit ncq pm led clo pmp pio slum part [ 19.703945] PCI: Setting latency timer of device 0000:03:00.0 to 64 [ 19.704033] scsi2 : ahci [ 19.704090] ata3: SATA max UDMA/133 abar [EMAIL PROTECTED] port 0xfd800100 irq 35 [ 20.342837] ata3: SATA link up 1.5 Gbps (SStatus 113 SControl 300) [ 20.385098] ata3.00: ATA-7: ST3500630AS, 3.AAK, max UDMA/133 [ 20.385100] ata3.00: 976773168 sectors, multi 16: LBA48 NCQ (depth 31/32) [ 20.443318] ata3.00: configured for UDMA/133 [ 20.443513] scsi 2:0:0:0: Direct-Access ATA ST3500630AS 3.AA PQ: 0 ANSI: 5 ... So there still seems to be a bug in the libata ahci driver 2.6.24-19.41 with the second port of SATA chipsets, as both the ULi and JMicron (JMicron 20360/20363 AHCI Controller [197b:2360] (rev 02)) chipsets on my ASRock 939Dual show no trouble at all with the disk (sda and sdc, respectively) connected to the first port: $ sudo hdparm -tT /dev/sdc /dev/sdc: Timing cached reads: 1674 MB in 2.00 seconds = 837.13 MB/sec Timing buffered disk reads: 188 MB in 3.01 seconds = 62.44 MB/sec Cheers, Lars ** Attachment added: "dmesg.log" http://launchpadlibrarian.net/17341708/dmesg.log ** Attachment removed: "version.log" http://launchpadlibrarian.net/17341707/version.log -- Slow SATA performance https://bugs.launchpad.net/bugs/119730 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
