Date: Mon, 12 Jul 2004 10:20:02 +0200 From: Martin Sommerhein <pms2-freebsd@sommerhein.com> To: freebsd-questions@freebsd.org Subject: Second harddrive as slave on ata0 (UDMA100) or as master on ata1 (UDMA33)? Message-ID: <20040712082002.GA50674@sommerhein.com>
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I am managing a remote machine where a second harddrive was added for me by the hosting company. I noticed that the second harddrive had been added as slave on the first IDE controller (ata0). As I assumed I would get better performance by having it as master on the second controller (ata1), I asked them to move the second drive over to the second master controller (ata1). So was done, but then I found that the same disk showed up as UDMA33 compared to UDMA100 when added as a slave to the first controller (ata0). Some info: ------------------------------------------------------------------- 1. Second disk as slave on ata0: # dmesg | grep ata atapci0: <Intel ICH4 ATA100 controller> port 0xffa0-0xffaf,0-0x3,0-0x7,0-0x3,0-0x7 at device 31.1 on pci0 ata0: at 0x1f0 irq 14 on atapci0 ata1: at 0x170 irq 15 on atapci0 ad0: 76319MB <WDC WD800BB-00CAA1> [155061/16/63] at ata0-master UDMA100 ad1: 76319MB <WDC WD800BB-00DKA0> [155061/16/63] at ata0-slave UDMA100 2. Second disk as master on ata1: # dmesg | grep ^ad ad0: 76319MB <WDC WD800BB-00CAA1> [155061/16/63] at ata0-master UDMA100 ad2: 76319MB <WDC WD800BB-00DKA0> [155061/16/63] at ata1-master UDMA33 ------------------------------------------------------------------- So the question is, what will give me the best performance, having it on the second master with UDMA33 or as a slave on the first controller as UDMA100? Best regards, Martin PS: Should this have been sent to freebsd-hardware@freebsd.org so please tell me?
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