Date: Wed, 30 Jun 2010 14:21:38 -0700 From: Jeremy Chadwick <freebsd@jdc.parodius.com> To: Paul Mather <paul@gromit.dlib.vt.edu> Cc: Alexander Motin <mav@freebsd.org>, FreeBSD Stable <freebsd-stable@freebsd.org> Subject: Re: Problems with ATA_CAM support in RELENG_8 Message-ID: <20100630212138.GA71370@icarus.home.lan> In-Reply-To: <1CD8E4CC-53C6-4594-9FF4-CDD57A6B51AC@gromit.dlib.vt.edu> References: <D77A24D9-8F38-42D4-996D-769352EE1C54@vt.edu> <AANLkTimPHAeu1lvqfgo2mX59aMPDOvu_GRJ94-GxQlz0@mail.gmail.com> <4C2B8103.6010409@FreeBSD.org> <1CD8E4CC-53C6-4594-9FF4-CDD57A6B51AC@gromit.dlib.vt.edu>
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On Wed, Jun 30, 2010 at 04:52:22PM -0400, Paul Mather wrote: > I thought ICH8 supported AHCI, but maybe it's only ICH8R that does? No, not necessarily. There are ICHxx (non-ICHxxR) models which definitely provide AHCI (ex. ICHxxM for their Mobile chipsets; yes, many laptops do have AHCI capability). Thus there are many different sub-models of ICH8, in addition to different perf/chip revisions of ICH8. Specification details: http://www.intel.com/assets/pdf/datasheet/313056.pdf http://www.intel.com/design/chipsets/specupdt/313057.htm Dell very likely chose not to engineer this particular motherboard to not provide AHCI capability (Option ROM space (usually included with the system BIOS), PCI and ICH8 register setups (done by the BIOS), etc.)). I know Gigabyte has done this with some of their boards as well. If you have concerns that your motherboard provides features that you can't use, you need to contact Dell. > I'm assuming that "subclass = ATA" means the controller can't operate > in AHCI mode. The BIOS setting is also confusing. It has two > options, "Normal" and "Legacy." "Normal" mode says, "The hard drive > controller is configured for native mode. This mode provides the > highest drive performance and most flexibility." I guess I > misinterpreted "native mode" to be AHCI mode. "Native", "Normal", and "Enhanced" are all terms used to describe the controller operating in standard SATA (non-AHCI) fashion. Dell's in-BIOS description is nothing but schmooze; it's not the same as AHCI. "Legacy" just means the controller appears and operates purely in PATA-esque mode, so that you can use SATA drives on systems which don't have SATA chipset drivers (ex. MS-DOS). To get an idea of what an AHCI-capable board offers via the BIOS, you should review the following manual for a Supermicro ICH7-based system. This chipset is older than yours, chosen for sake of example. See Chapter 7-3, section "Main Setup Features": http://www.supermicro.com/manuals/superserver/1U/MNL-0813.pdf Furthermore, I can assure you that the Dell OptiPlex 745 Mini-Tower offers AHCI capability, and toggling its use via the system BIOS. You won't find it mentioned in Dell's "Tech Specs" PDF about this though. I realise this is not the system you have, but I'm simply pointing out that it's a board manufacturer decision whether or not to provide the capability, and that their decision obviously changed over the years. -- | Jeremy Chadwick jdc@parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |
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