Re: 2.4 disk speed 66% slowdown...

Andre Hedrick
2001-01-24T05:13:31Z

On Tue, 23 Jan 2001, Linda Walsh wrote:

> Mine was actually out of a stock 2.2.17 -- I tried your patch in an attempt
> to fix a disk problem - but the disk was just going bad and the slow speeds were
> coming from the automatic sector remapping.
>
> pardon my ignorance, but where do you get UDMA-100-66?

Well:
> > > It's an Intel i815 motherboard, and the HDD is Ultra-ATA.

i815 is an Ultra DMA 100 SouthBridge core.

> Here is the hdparm -i output on 2.4:
>
> /dev/hda:
>
> Model=IBM-DARA-225000, FwRev=SHAOA54A, SerialNo=SQASQ202564
> Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs }
> RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=4
> BuffType=3(DualPortCache), BuffSize=418kB, MaxMultSect=16, MultSect=off
> DblWordIO=no, OldPIO=2, DMA=yes, OldDMA=2
> CurCHS=17475/15/63, CurSects=16513875, LBA=yes, LBAsects=49577472
> tDMA={min:120,rec:120}, DMA modes: mword0 mword1 mword2
> IORDY=on/off, tPIO={min:240,w/IORDY:120}, PIO modes: mode3 mode4
> UDMA modes: mode0 mode1 *mode2 mode3 mode4
> Drive Supports : ATA/ATAPI-4 T13 1153D revision 17 : ATA-1 ATA-2 ATA-3 ATA-4
>
> UDMA mode (2) seems to be identical to before.

Also, if your drive is caught in the question state of where the standard
changes, the validity bits for determining the host/drive detection pair
for the presense willl be fuzzy as is my explaination.

>
>
> Andre Hedrick wrote:
> >
> > On Tue, 23 Jan 2001, Florin Andrei wrote:
> >
> > > Linda Walsh wrote:
> > > >
> > > > The REAL problem was in disk performance. The apm made no difference:
> > >
> > > Same problem here. I had a huge HDD performance drop when upgrading
> > > from 2.2.18 to 2.4.0
> > > It's an Intel i815 motherboard, and the HDD is Ultra-ATA.
> >
> > ER, were you getting UDMA-100-66 out of 2.2.18 stock?
> > Now what are you getting in 2.4.0?
>
> --
> Linda A Walsh | Trust Technology, Core Linux, SGI
> law@sgi.com | Voice: (650) 933-5338
>

Andre Hedrick
Linux ATA Development