Messages in this thread | | | Date | Tue, 1 Dec 1998 22:02:54 -0600 (CST) | From | "Andre M. Hedrick" <> | Subject | Re: IDE-DMA strangeness (another one) |
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On 1 Dec 1998, Mark Gray wrote:
> Rik van Riel <H.H.vanRiel@phys.uu.nl> writes: > > > > > Hi, > > > > I've just moved my IDE disks around, taking out an old > > disk and moving my new 6.4GB disk from hdd to hda.
This sounds normal.............name your chipset........did you happen to run 'W-word'? Older PIIX's lie about capabilty because of crappy BIOS writers/hackers............
> > With this move I saw in improvement (hdparm -t) from 3 > > to 8.4 (!) MB/second... Now I wonder what kind of bug
Your PIO3/4 disk that had a recomended of 180ns for DMA was locked out. The previous location was a non-correctly allocated PDT. Skip the assigned PIO settings in the bios and use AUTO/AUTO
> > in the Linux I/O subsystem could hold performance back > > _that_ badly.
Not a bug...........8.4 MB/second is a UDMA drive at DMA mode 2 on an 430HX/VX/TX, and I bet the usable buffer is more. Note that the new kernel code auto set multi-write to max.
> > Of course both benchmarks were done on a completely > > unloaded IDE chip/PCI bus... > > Some motherboards use a crippled controller for ide1 in the belief > that it will only be used for cdroms.
That is usually because of lazy BIOS writers/hackers (ass)(u)(me) "Nobody will use more than two hardrives"
> > cheers, > > > > Rik -- now completely used to dvorak kbd layout... > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.rutgers.edu > Please read the FAQ at http://www.tux.org/lkml/ >
Cheers, Andre Hedrick The IDE-FNG for Linux The APC UPS Specialist for Linux
http://www.dyer.vanderbilt.edu/server/udma/ http://www.dyer.vanderbilt.edu/server/apcupsd/apcupsd-3.5.0.bin.tar.gz
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
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