Re: My drive only operates in UDMA2?
On Wed, 11 Feb 2004, Andreas Janssen wrote:
> Darin Strait (<firstname.lastname@example.org>) wrote:
> > I'm troubleshooting something that has been bugging me for a while...
> > Why does my drive seem to run only in UDMA2 and only do about 19.50
> > MB/s, according to hdparm? Everyone else always seems to have a faster
> > drive than me, so I'm assuming that I'm misconfiguring something and
> > it's not my hardware.
> > I have fiddled with idebus=66 in my grub menu.lst, but it has never
> > seemed to have an effect.
> Please don't change that parameter if you don't really know what it
> does. idebus is the speed in Mhz that the IDE bus uses. This has
> nothing to do with ATA33 or ATA66. The ATA numbers name the theoretical
> data throughput in MB/s. Unless you use some server mainboard your
> system very probably only supports a bus speed of 33 MHz.
or risk losing everything on disk... not a biggie ... a good way
to test backups :-)
> > I have an i810e motherboard and I'm running 2.6.2 (other kernel
> > versions have had similar results). I have a Western Digital WD1200BB
> > drive, the specs are as follows:
> > [...]
> > - Mode 5 Ultra ATA 100.0 MB/s
that'd tell me that the disk is capable of udma5...
but the mb is NOT recognizing it ...
- check your bios ...
- check your cables as andreas said - use the 80conductor cable
- do NOT use round cables
> > DMA modes: mdma0 mdma1 mdma2
> > UDMA modes: udma0 udma1 *udma2
something is seriously broken ... on your system ...
> > [...]
> > * signifies the current active mode
> No. It signifies the mode that is used /if/ DMA is activated. If you
> switch of DMA it will still tell you *udma2.
and dma is enable so its good ... but the hdparm says it doesnt
support udma3/4/5 ...
- either the specs is wrong or the bios is broken
> > Timing buffer-cache reads: 288 MB in 2.02 seconds = 142.31 MB/sec
> > Timing buffered disk reads: 58 MB in 3.01 seconds = 19.27 MB/sec
> My guess: wrong type of cable. Make sure it can do more that udma2.
but for udma2, something is seriously broken on your system
( you're at high risk to have your disk trashed )
udma2 - 13MB/sec ( whacky new xfer vs PIO modes )
udma3 - 16MB/sec
umda4 - 33MB/sec
udma5 - 66MB/sec
udma6 - 100MB/sec
udma7 - 133MB/sec