Re: speed trends in pata world.

[Bill Davidsen <davidsen@tmr.com>]

Gene Heskett wrote:
> Greetings;
> 
> The drive speeds seem to be going the wrong way.  Its an nforce2 equipt mobo, 
> and I have 3 drives currently in this box.  Running 2.6.22-rc6-cfs-v18 + the 
> ftdi_sio.c patch.
> 
> hda, the primary on cable 0, is running at around 28MB/Sec.  Its a 200GB WD 
> about 2 years old.
> 
> hdb, is running at around 79MB/Sec, its a 4 year old 120GB WD.
> hdd is running at about 75MB/Sec, is a nearly new 300GB WD.
> 
> Can I read anything into the fact that the 2 fast drives are on the slave end 
> of the cables, whereas the slow one is master in the middle of the cable?
> 
First look at dmesg and see what it tells you. Second, if there is a 
slow device on the cable it will sometimes limit the speed of the disk. 
Alan Cox and God might know why, I don't.

Third, you can play with drive parameters with hdparm. *DANGEROUS* to do 
so, the man page says "needless and risky," but at least the older 
kernels truly sucked at guessing the correct speeds. Backups are advised 
if you do this, etc,etc.

-- 
Bill Davidsen <davidsen@tmr.com>
   "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot