Date: Mon, 1 Dec 2003 00:23:37 -0600 (CST) From: James Van Artsdalen <james-freebsd-amd64@jrv.org> To: freebsd-amd64@freebsd.org Subject: Re: disk controllers w/ 64-bit addressing? Message-ID: <200312010623.hB16Nbbd032872@bigtex.jrv.org>
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I don't think PIO transfers for s/ATA would be as fast as DMA with bounce-buffers. Current ATA disk drives can sustain 60 MB/s in the fast zones. I'm wondering if anyone else has done the exercise of looking for a fast disk system for an AMD64 with more than 4 GB of RAM. I would prefer to stay with serail-ATA instead of expensive SCSI but I don't know if any serial-ATA controllers can directly write to memory above 4 GB without a bounce buffer, or if there is a FreeBSD driver for such a controller. Date: Sun, 30 Nov 2003 10:31:40 -0500 From: Dave Feustel <dfeustel@mindspring.com> Subject: Re: disk controllers w/ 64-bit addressing? 64-bit memory addressing for disk transfers can be done in AMD native mode via programmed i/o. The question is whether 64-bit memory addressing via dma-controlled memory transfers is possible and/or supported via the disk driver.
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