Date: Fri, 8 Feb 2008 18:37:01 +0100 From: Pieter de Goeje <pieter@degoeje.nl> To: freebsd-stable@freebsd.org Cc: Tom Evans <tevans.uk@googlemail.com>, Dominic Fandrey <kamikaze@bsdforen.de>, "Carlos A. M. dos Santos" <unixmania@gmail.com> Subject: Re: RELENG_7: interrupt eating whole cpu core Message-ID: <200802081837.01676.pieter@degoeje.nl> In-Reply-To: <1202491071.2126.42.camel@localhost> References: <47A9F835.1060200@bsdforen.de> <47AC7FF6.1020801@bsdforen.de> <1202491071.2126.42.camel@localhost>
next in thread | previous in thread | raw e-mail | index | archive | help
On Friday 08 February 2008, Tom Evans wrote: > On Fri, 2008-02-08 at 17:14 +0100, Dominic Fandrey wrote: > > Tom Evans wrote: > > > If I try to turn on DMA, I just get WDMA2, which just doesn't cut it: > > > > I think any DMA mode is fast enough to handle a DVD drive. There's just > > no necessity for more. > > WDMA is not UDMA. Any UDMA variant would be enough. WDMA2 provides a > maximum of 16MiB/s, which will frequently lead to buffer underruns > viewing a DVD. UDMA2 provides a maximum of 33MiB/s, which IS plenty. DVD video is encoded at max. ~7Mbit/sec, which is way below 16MB/sec. You should have no problems viewing dvds. > > > >> # atacontrol mode acd0 udma5 > > > > > > current mode = WDMA2 > > > > Same as for me. I'm satisfied with the speed of the drive. > > I'm rarely satisfied - I'm quite often not bothered enough to pursue :) > > Tom -- Pieter de Goeje
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200802081837.01676.pieter>