Date: Mon, 04 Jun 2007 01:23:08 -0500 From: Tim Daneliuk <tundra@tundraware.com> To: r17fbsd@xxiii.com Cc: freebsd-questions@freebsd.org Subject: Re: Strange Intel Mobo Behavior Message-ID: <4663AFCC.6080508@tundraware.com> In-Reply-To: <6.2.3.4.2.20070603232531.03dffe40@mailsvr.xxiii.com> References: <46630382.8010901@tundraware.com> <6.2.3.4.2.20070603232531.03dffe40@mailsvr.xxiii.com>
next in thread | previous in thread | raw e-mail | index | archive | help
r17fbsd@xxiii.com wrote: > At 02:08 PM 6/3/2007, Tim Daneliuk wrote: >> 3) Both the MOBO and drive are SATA-300 rated, but 6.2 insists that >> the drive is running at SATA-150. I have verified that the drive >> has no jumper forcing it into this mode. > > Don't know about the other issues, but I have a Dell with similar Intel > components, and it did the same SATA thing when I put a new drive in it > yesterday: > > atapci1: <Intel ICH7 SATA300 controller> port > 0xfe00-0xfe07,0xfe10-0xfe13,0xfe20-0xfe27,0xfe30-0xfe33,0xfea0-0xfeaf > irq 20 at device 31.2 on pci0 > ad4: 76293MB <Maxtor 6L080M0 BACE1G10> at ata2-master SATA150 > ad6: 305245MB <Seagate ST3320620AS 3.AAK> at ata3-master SATA150 > > The ad6 drive is supposed to do SATA-300, but realistically, other > bottlenecks dictate it's not going to get anywhere near the '150 speed, Could you comment a bit more on why you think this is so. I would think that with modern processors and buses, a machine with light load ought to be able to drive SATA-300, but I've never actuall tested for it myself. > so I'm not terribly worried about it. cp'ing a 4GB file to /dev/null > yielded 57MB/sec. > > -RW I get around 50MB/sec or so with about 2G file, so we're in the same ballpark. In round numbers, this is 1/3 the theoretical throughput of a SATA-150 or 1/6 that of SATA-300. Now, I *am* curious on what the bottlenecks are. 50MB/sec isn't a whole lot different that what I'd expect out of a modern PATA drive. So, noting the better cabling and the wide availability of on-board RAID, it sure looks to me like there is no compelling argument to be made for SATA in non-RAIDed environments. I'm guessing the drives are the same ones as their PATA counterparts, just with different interface electronics, so we're not going to see SCSI-like reliability and/or performance under load. I can understand some overhead due to system dispatching and multitasking, but in a lightly loaded machine (as mine was when I did the test) with 2G of memory and dual 3.2G processors, it seems very strange that the drive should run at 1/3 or less the stated interface speed. What am I missing here, I wonder... ---------------------------------------------------------------------------- Tim Daneliuk tundra@tundraware.com PGP Key: http://www.tundraware.com/PGP/
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4663AFCC.6080508>