Gregory K. Ruiz-Ade wrote:
I'm working on some problems on my mythbox, and in the course of
examining the system, I find that my HD is only negotiating SATA1
(1.5Gbps), instead of SATA2 (3.0Gbps), which both the HD and board
support. The motherboard is an Intel DP35DPM and the drive is a Seagate
Barracuda ES 750GB (ST3750640NS).
Anyone have any ideas as to why I'm not getting the full capability?
How did you determine that the drive is only working in 1.5Gbps vs 3.0 Gbps?
Is the BIOS set up correctly? You need to ensure it has SATA mode
selected and not IDE (ref
<http://www.intel.com/support/motherboards/desktop/sb/cs-020811.htm> )
Maybe you need to upgrade to the latest BIOS if you haven't already.
Is Linux showing you that it is using the AHCI driver? Which kernel are
you running? What does dmesg show you it detected when it starts?
Starting with kernel 2.6.21, the IDE/ATA access layer underwent major
restructuring, which includes the SATA drivers. That's why everything
now shows up as /dev/sd? You might try the latest kernel. Boot a Fedora
Test 3 LiveCD (or something similar) which has kernel 2.6.23-rc8 and see
if that makes any difference.
Maybe you have problems with a bad cable/connection. This is from the
Linux Kernel Documentation for libata:
Reconfigure transport
For both PATA and SATA, a lot of corners are cut for cheap
connectors, cables or controllers and it's quite common to see
high transmission error rate. This can be mitigated by
lowering transmission speed.
The following is a possible scheme Jeff Garzik suggested.
If more than $N (3?) transmission errors happen in 15 minutes,
if SATA, decrease SATA PHY speed. if speed cannot be decreased,
decrease UDMA xfer speed. if at UDMA0, switch to PIO4,
decrease PIO xfer speed. if at PIO3, complain, but continue
Finally, it is not going to make any difference because the throughput
of the drive is much lower than the interface. You will never see any
benefit from going to 3.0Mbps.
Gus
--
[email protected]
http://www.kernel-panic.org/cgi-bin/mailman/listinfo/kplug-list
