Date: Fri, 30 May 2003 10:04:39 -0700 From: Kent Stewart <kstewart@owt.com> To: Rich Morin <rdm@cfcl.com>, freebsd-questions@freebsd.org Subject: Re: Boot problem: "ata0: resetting devices" Message-ID: <200305301004.39445.kstewart@owt.com> In-Reply-To: <p05200f2abafd3ad5b917@[192.168.254.205]> References: <p05200f16bafb423c7331@[192.168.254.205]> <200305300729.41685.kstewart@owt.com> <p05200f2abafd3ad5b917@[192.168.254.205]>
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On Friday 30 May 2003 09:50 am, Rich Morin wrote: > At 7:29 AM -0700 5/30/03, Kent Stewart wrote: > >I use the Promise TX2 and Maxtor pci cards in several systems. I > >just dropped them in and they worked. You would have to boot scsi. > > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > So, you're saying that I can't boot from an ATA drive on a PCI-based > controller card? What is the background for this limitation? No, you didn't understand. The ATA cards appear like a scsi to the bios. To boot from an add in ATA card, you have to choose scsi boot. > > Also, I'm curious about the effects of turning off hw.ata.ata_dma; > outside of using some CPU time, what are the likely effects of this. > For instance, is this likely to slow down disk transfers, assuming > that the system is mostly idle? You lose a lot of speed. My new ATA cards are all UDMA-133. Dma transfers are always faster. PIO is set at something like 16MB/s. You only get so many milliseconds of time for a each transfer block and dma is always faster. Kent -- Kent Stewart Richland, WA http://users.owt.com/kstewart/index.html
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