Re: HELP: UDMA/100 woes and trouble.
On Thursday 27 September 2001 02:12 pm, Peter S Galbraith wrote:
> Peter Jay Salzman wrote:
> > i'm having a HECK of a time trying to get UDMA/100 transfer speeds on my
> > system.
> >
> > hdparm -t reports 35 MB/s. this is nowhere near the 100MB/s that i'm
> > expecting to get.
>
> Why are you expecting 100MB/s? That's the bus maximum bandwidth.
> It doesn't mean you can physically read data off the disk platter
> that fast.
>
> (5 years ago I was happy to get 7 MB/s of a disk.)
Yeah, that's pretty much where I stand today... I've got an old ATA33 disk.
It's a Quantum Fireball 30GB disk. What sort of throughput should I be
getting?
nebula:/home/jasonb# hdparm -t -T /dev/hdb
/dev/hdb:
Timing buffer-cache reads: 128 MB in 2.09 seconds = 61.24 MB/sec
Timing buffered disk reads: 64 MB in 8.96 seconds = 7.14 MB/sec
/dev/hdb:
multcount = 16 (on)
I/O support = 0 (default 16-bit)
unmaskirq = 0 (off)
using_dma = 0 (off)
keepsettings = 0 (off)
nowerr = 0 (off)
readonly = 0 (off)
readahead = 8 (on)
geometry = 3649/255/63, sectors = 58633344, start = 0
Last time I messed with hdparm and tried to tweak the settings I ended up
with WORSE performance (I believe I ended up with 4MB/sec buffered disk reads
instead of 7MB/sec).
Ideas?
> Peter
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