On Wednesday, March 16, 2011 15:38:47 Allen Weiner wrote: > Linux (both Fedora 14 and Ubuntu 10.10) is limiting my UDMA/133 PATA HDD > (my main system drive) to UDMA/33: > > 1.861688] ata7.00: ATA-7: Maxtor 6Y080L0, YAR41BW0, max UDMA/133 > [ 1.861928] ata7.00: 156250000 sectors, multi 0: LBA > [ 1.862181] ata7.00: limited to UDMA/33 due to 40-wire cable > [ 1.868673] ata7.00: configured for UDMA/33 > > My IDE cable is an 80-wire cable (it has blue and black end-connectors > and a gray center-connector). The cable is connected with the correct > orientation (blue end-connector connected to motherboard, black > end-connector is connected to HDD). There is nothing connected to the > center connector. The HDD is jumpered for CS (cable-select).
Using cable select is typical, but is less reliable than using "single mode" for when a hard disk is alone on a cable. It's interesting that Linux is reporting that you're using a 40-pin cable when you're using an 80-pin cable. The 80-pin cable is doing ground/signal/ground, by the way -- so only 40 pins of that 80-pin cable are actually used for ATA transmission. > The BIOS recognizes the HDD as UDMA/133. On bootup the BIOS displays a > screen which lists the HDD as UDMA mode 6 (which is UDMA/133). > Initially, I attached the IDE cable with the backward orientation, and > the BIOS recognized the HDD as UDMA mode 2 (UDMA/33). > > The HDD is a Maxtor DiamondMax Plus 9 6Y080L0 80 GB PATA. The > motherboard IDE controller is VIA VT6330. > > 04:00.1 IDE interface: VIA Technologies, Inc. PATA IDE Host Controller > (rev a0) (prog-if 85 [Master SecO PriO]) > Subsystem: VIA Technologies, Inc. PATA IDE Host Controller > Flags: bus master, fast devsel, latency 0, IRQ 16 > I/O ports at e800 [size=8] > I/O ports at e400 [size=4] > I/O ports at e000 [size=8] > I/O ports at d800 [size=4] > I/O ports at d400 [size=16] > Expansion ROM at fe9f0000 [disabled] [size=64K] > Capabilities: [50] Power Management version 3 > Capabilities: [70] MSI: Enable- Count=1/1 Maskable+ 64bit+ > Capabilities: [90] Express Legacy Endpoint, MSI 00 > Capabilities: [100] Advanced Error Reporting > Capabilities: [130] Device Serial Number 00-30-67-ff-ff-83-f3-23 > Kernel driver in use: pata_via > Kernel modules: pata_via > > > A Google search shows that there are a number of bug reports for this > type of problem, but they are not recent: > > 1. Red Hat Bugzilla – Bug 429774 > pata_via 40-wire cable wrong detection > Last modified: 2008-11-26 12:37:12 EST > > 2.Kernel Bug Tracker – Bug 10179 > pata_amd libata: Erroneous "limited to UDMA/33 due to 40-wire cable" > from PX-130A > Last modified: 2008-06-18 03:28:03 > > 3.Kernel Bug Tracker – Bug 8164 > pata_via: wrong cable detection on PATA controller > Last modified: 2007-03-21 13:11:17 > > Questions: > --------- > > Q1: Is this a user error (something I'm overlooking in my hardware > setup) or a Linux bug? I believe Linux by default uses UDMA/33 for compatibility reasons, but I'm not exactly sure how the speed decision is decided at boot time. Have a look at the 'hdparm' package, which allows you to manually set hard disk parameters like the ATA speed as well as 32-bit access mode. 'hdparm' is only useful for ATA/IDE hard disk access, by the way -- it won't work for SATA or SCSI if I remember correctly. > Q2: If this is a Linux bug, should I try to reopen RedHat Bug 429774 or > submit a kernel bug report to kernel.org? (the bug occurs on Fedora 14 > and Ubuntu 10.10) Maybe. It depends on why Linux is defaulting to using UDMA/33 mode in this case. It might be because of a known ATA controller quirk. Donno. Might be worth investigating the reason. > Q3. I plan to eventually buy a SATA HDD. I'm waiting for a 4K sector HDD > (aka "Advanced Format") which does not do 512-byte sector emulation, i.e > 4K native. In the meantime, if someone in the group within a 10-mile > radius of downtown Poughkeepsie has an unwanted SATA HDD, make me an > offer. IIRC Linux was patched for the 4K sector "Advanced Format" problem that Windows 2000 ran into, so that shouldn't be a factor. -- Chris -- Chris Knadle [email protected] _______________________________________________ Mid-Hudson Valley Linux Users Group http://mhvlug.org http://mhvlug.org/cgi-bin/mailman/listinfo/mhvlug Upcoming Meetings (6pm - 8pm) MHVLS Auditorium Apr 6 - Introduction to IPv6 May 4 - Inkscape Jun 1 - Zimbra
