Comment 63 for bug 119730

Just to add some more input on the problem, that nobody seems to have been able to resolve yet:

On my system (Linux sigma 2.6.24-19-generic #1 SMP Fri Jul 11 21:01:46 UTC 2008 x86_64 GNU/Linux), the only harddrive affected by the SATA performance bug (5MB/sec max.) is the one on the second port (even though it is identical to the one on the first port of my 00:12.1 IDE interface: ALi Corporation ULi 5289 SATA (rev 10), see below):

steinke@sigma:~$ sudo hdparm -tT /dev/sdb
/dev/sda:
 Timing cached reads: 1702 MB in 2.00 seconds = 851.45 MB/sec
 Timing buffered disk reads: 228 MB in 3.01 seconds = 75.62 MB/sec

steinke@sigma:~$ sudo hdparm -tT /dev/sdb
/dev/sdb:
 Timing cached reads: 1100 MB in 2.00 seconds = 550.14 MB/sec
 Timing buffered disk reads: 10 MB in 3.61 seconds = 2.77 MB/sec

This is also reflected by the SATA initialisation ("configured for PIO" instead of "configured for UDMA/133"), forcing UDMA with hdparm has no effect either...

dmesg:
...
[ 18.319314] scsi2 : ata_generic
[ 18.319369] scsi3 : ata_generic
[ 18.319481] ata3: PATA max UDMA/100 cmd 0xec00 ctl 0xe080 bmdma 0xd880 irq 19
[ 18.319482] ata4: PATA max UDMA/100 cmd 0xe000 ctl 0xdc00 bmdma 0xd888 irq 19
[ 18.522204] ata3.00: ATA-7: ST3320620AS, 3.AAE, max UDMA/133
[ 18.522206] ata3.00: 625142448 sectors, multi 16: LBA48 NCQ (depth 0/32)
[ 18.522216] ata3.00: configured for UDMA/133
[ 18.727409] ata4.00: ATA-7: ST3320620AS, 3.AAE, max UDMA/133
[ 18.727411] ata4.00: 625142448 sectors, multi 16: LBA48 NCQ (depth 0/32)
[ 18.727419] ata4.00: configured for PIO
[ 18.727456] scsi 2:0:0:0: Direct-Access ATA ST3320620AS 3.AA PQ: 0 ANSI: 5
[ 18.727561] scsi 3:0:0:0: Direct-Access ATA ST3320620AS 3.AA PQ: 0 ANSI: 5
...
[ 21.453463] ahci 0000:03:00.0: version 3.0
[ 21.453493] ACPI: PCI Interrupt 0000:03:00.0[A] -> GSI 35 (level, low) -> IRQ
 35
[ 21.456918] Driver 'sd' needs updating - please use bus_type methods
[ 21.456990] sd 2:0:0:0: [sda] 625142448 512-byte hardware sectors (320073 MB)
[ 21.457000] sd 2:0:0:0: [sda] Write Protect is off
[ 21.457002] sd 2:0:0:0: [sda] Mode Sense: 00 3a 00 00
[ 21.457014] sd 2:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 21.457049] sd 2:0:0:0: [sda] 625142448 512-byte hardware sectors (320073 MB)
[ 21.457056] sd 2:0:0:0: [sda] Write Protect is off
[ 21.457057] sd 2:0:0:0: [sda] Mode Sense: 00 3a 00 00
[ 21.457068] sd 2:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 21.457070] sda: sda1 sda2 sda3 sda4 < sda5 sda6 sda7 sda8 >
[ 21.518700] sd 2:0:0:0: [sda] Attached SCSI disk
[ 21.518759] sd 3:0:0:0: [sdb] 625142448 512-byte hardware sectors (320073 MB)
[ 21.518768] sd 3:0:0:0: [sdb] Write Protect is off
[ 21.518770] sd 3:0:0:0: [sdb] Mode Sense: 00 3a 00 00
[ 21.518782] sd 3:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 21.518816] sd 3:0:0:0: [sdb] 625142448 512-byte hardware sectors (320073 MB)
[ 21.518822] sd 3:0:0:0: [sdb] Write Protect is off
[ 21.518824] sd 3:0:0:0: [sdb] Mode Sense: 00 3a 00 00
[ 21.518835] sd 3:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 21.518837] sdb: sdb1 sdb2 sdb3 sdb4 < sdb5 sdb6 sdb7 sdb8 >
[ 21.593424] sd 3:0:0:0: [sdb] Attached SCSI disk
...

hdparm -I output attached, which mysteriously enough shows no discrepancy between those two drives at all...

Regards,
Lars