SATA300

[Erik Trulsson]

On Sat, Jul 26, 2008 at 11:22:26PM -0400, Jason Lenthe wrote:
> My machine, a home-brew running 7.0-RELEASE-p2, has 3 SATA hard drives 
> all of which were advertised as SATA300 drives, but:
> 
> vader# dmesg | grep ATA
> ata0: <ATA channel 0> on atapci0
> ata1: <ATA channel 1> on atapci0
> atapci1: <Intel ICH7 SATA300 controller> port 
> 0x20c8-0x20cf,0x20ec-0x20ef,0x20c0-0x20c7,0x20e8-0x20eb,0x20a0-0x20af 
> irq 19 at device 31.2 on pci0
> ata2: <ATA channel 0> on atapci1
> ata3: <ATA channel 1> on atapci1
> ad4: 305245MB <Hitachi HDT725032VLA360 V54OA7EA> at ata2-master SATA150
> ad5: 476940MB <MAXTOR STM3500630AS 3.AAE> at ata2-slave SATA150
> ad6: 305245MB <Hitachi HDT725032VLA360 V54OA7EA> at ata3-master SATA150
> 
> Does this mean I'm only getting half the throughput I could be getting?

Considering that the fastest SATA drives available today tops out at a
throughput of about 120MB/s (and most are quite a bit slower), I would say
that any speed loss from running at SATA150 speed instead of SATA300 will be
fairly minor and probably not even noticable.


Many SATA hard drives have a jumper that can be used to limit them to
SATA150 speeds.  It is often set by default, since some older SATA
controllers fail to auto-negotiate speed correctly, so the drive must
be running at SATA150 to work with those controllers.
See if you drives have such a jumper set.  If so try removing it.



-- 
<Insert your favourite quote here.>
Erik Trulsson
ertr1013 at student.uu.se