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Re: Desktop Performance Issue



hi ya bruce

> > >    >/dev/hda:
> > >    > setting using_dma to 1 (on)
> > >    > HDIO_SET_DMA failed: Operation not permitted
> > >    > using_dma    =  0 (off)
> > >
> > > Do it as root
> 
> of course
> 
> > sometimes .. you have to make sure that the chips and
> > the drive supports DMA ...
> > 	- ( check the kernel IDE/dma options )
> 
> I think it is the chips which don't do DMA.
> circa 1990 hardware

ah ... first problem.....  those circa drives supports
multiword dma ... not ultra-dma .... 

which exactly is supported...
	hdparm -iv /dev/hda  will tell you
 
> command line after boot, right?
> 
> hmmm...
> # CONFIG_IDEDMA_AUTO is not set
> # CONFIG_DMA_NONPCI is not set

and if that is the kernel you're booting... 
	hdparm options int he bootups will not work

> I'm curious about the PIO modes, and if one of those is what is being
> used.  Since the drive is defaulting to a DMA mode but the OS isn't
> doing DMA, is the system falling back to PIO and should explicitly
> selecting the best PIO mode be expected to improve performance.

the list of dma options  from hdparm -iv wil tell you which
one ( marked w/ * )  your machine is currently using  
 
> gotta lot of reading and fiddling to do

pio vs udma vs dma vs ...
	http://www.Linux-1U.net/Disks/

and for system fiddling and tuning
	http://www.Linux-1U.net/Tuning

c ya
alvin



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