Messages in this thread | | | Date | Wed, 10 Nov 1999 20:02:23 -0800 (PST) | From | Dan Hollis <> | Subject | Re: disk corruptions on "tuned" disks Was: APM killing low-latency performance on BX mainboard |
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On Thu, 11 Nov 1999, Benno Senoner wrote: > On Thu, 11 Nov 1999, Dan Hollis wrote: > > > thanks, but what is the exact problem source , DMA or unmask IRQ ? > > DMA > > > I'm watching DVDs for hours ( DMA enabled) without any lockups. > > It may be ultra dma only bug. Im not sure. My DVDROM and CDROM both > > support udma. > I don't played with UDMA on CDROMS, only simple DMA. > I don't care about a potential UDMA bug,
Lots of people do. For instance me 8)
> simple DMA solves all latency problems, and the performance > difference between DMA and UDMA on a CDROM drive is almost > zero. (since the CDROM is the bottleneck).
Try a 72x cdrom sometime. Yes they do exist.
> > > But are you sure that every ATAPI CDROM drive on the planet > > > has this hardware flaw. > > Its the controller not the CDROM at fault > are you sured that the BX chipset is flawed ? > It seems to work well.
I never said the Intel 440bx chipset is flawed. I said the VIA VP3/MVP3/MVP4 is flawed. 440bx is fine AFAIK.
> > > I stressed my CDROM drives quite a bit, and was unable to lock up the box. > > What controller and what drives > Mainboard Gigabyte GA 6BXD (dual) with BX chipset.
Then you should be ok
> > > How is this handled my other OSes ? > > They dont run DMA. > Wrong: try to dig on deja.com searching articles about > DVD software playback on windoze: > for most people it is almost impossible to get skipfree video > without DMA.
This is irrelevant if the controller cant run DMA (eg promise u66).
> > > > Promise Ultra66. No DMA on CDROM/DVDs. It just wont work. At all. > > > PS: why should recent ATAPI CDROM let you set the DMA mode, when they > > > know that it could lead to problems ? > > Its the controller not the CDROM at fault > I was wondering how much % of the controllers are faulty in this respect.
Lots. All VIA VP3/MVP3/MVP4 boards for example. This is a large percentage of boards now shipping, especially asia
-Dan
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