Messages in this thread |  | | Date | Fri, 01 Dec 2000 09:44:01 -0500 | From | Mike Dresser <> | Subject | Re: DMA for triton again... |
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Guennadi Liakhovetski wrote:
> Hi > > will try tonight... and will let you know tomorrow... > ... Nop, it didn't work. Mike and everybody having experience / knowledge of Western Digital Caviar AC21600H... If you compare WD's documents at: > http://www.westerndigital.com/service/FAQ/dtr.html > and > http://www.westerndigital.com/products/non-current/drives/ac21600.html > they, respectively ,say: > > UDMA if CCC is A8-AG (AH is not UDMA), D5-D7, Bx, or Cx All others -- PIO Mode 4 > > and > > 16.6 MB/s (burst Mode 4 PIO) * > 16.6 MB/s (burst Mode 2 DMA) ** > 33.3 MB/s (Mode 2 Ultra DMA) *** > > *Max PIO burst rate is specified at 16.6 MB/s using the IORDY signal. > **Max DMA and multi-word DMA burst rate is specified using the DMARQ and DMACK signals. > ***Mode 2 Ultra DMA is supported in the following firmware revisions (CCC Codes: A8, AA, AC, AD, AG, D5, D6, D7, Bx, Cx). > > Which one is true? Do non-UDMA AC21600H (I've got CCC F6) support DMA? > > Is it possible to find out where hdparm -d1 is stopped? Maybe by compiling it with -g and debugging... As far as I understand, BIOS is not an issue, since ide.txt says, that Linux doesn't use BIOS when working with hard drives... > > Thanks > Guennadi > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > Please read the FAQ at http://www.tux.org/lkml/
Well, per my other email, i found a case where the bios DID matter. Yes, the AC21600H supports DMA. Even my dinosaur 850 meg in that same box, works in dma mode, and does get a little bit faster. They're so slow in the first place that it doesn't make much transfer rate difference, but the cpu load goes way down.
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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