On Friday 22 December 2000 17:53, you wrote:
> --- Buchan Milne <[EMAIL PROTECTED]> wrote:
> > controller. Can't wait to see what a decent HD (IBM
> > 30-75GXPs) can do.
>
> I have a 30 GB 75GXP switched to ATA100, after the
> hdparm tuning(I don't remember the parameters, I am at
> work) I get around 35 MB/s.
>
> Is this the expected xfer rate for ATA100 drives?
> Is the kernel on 7.2 compiled for ATA100, or do I have
> to compile the kernel for ATA100 and hope to get still
> better results.
It IS compiled for ATA/100 which leads to many problems for those with
slightly off-spec hardware. I am sure you have seen the posts ("worked in
Windows, Worked in RH, Worked in 7.1....")
Well, in chasing a write error on bug reports, I discovered an ATA/66 drive
that gave 19.10 Mb/s at udma4 and 19.34Mb/s at udma2. Obviously this drive
was advertising to the controller that it was capable of more that it could
do. (It autotuned to ATA/66(udma4) but worked properly at udma2).
Many things can affect the data rate. I have seen some ATA/66s hit 28 or 29
Mb/s on that test. If the disk is 7200 rpm instead of 5400, that can make a
difference as well. My personal feeling is that ATA/33+ is pretty much all
the same except for the price and the tests. Using a several hundred
megabyte partition to partition copy on the same disk, I achieved data rates
of 1.7 Mb/s using each of the three technologies. Using disks on different
ide channels, I managed 2.7, 2.7, and 2.8Mb/s. Within the possibility of the
error of representing something (practically) continuous and infinite with
something finite and discrete, those results are basically identical.
Perhaps the copying of data does not give enough room to burst mode as a
significant factor, and YMMV by mobo, processor, controller, and the phase of
the moon, but I am wondering if the numbers are there more to attract the
contents of our wallets than to represent any real gain in performance.
Civileme
>
> Cheers
> Sridhar
>
>
> =====
> Good judgement comes from experience,
> experience comes from bad judgement
>
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