Re: New IDE drive dramatically slow system?
On Mon, 7 Jul 2003, Carl Fink wrote:
> On Mon, Jul 07, 2003 at 02:34:35AM -0700, Alvin Oga wrote:
>
> > you cannot mix different speed drives on the same ide cable ...
> > - similarly, you cannot mix 2MB buffer disks with 8MB buffer disks
> > ( the hw doesnt know what to do )
>
> That's odd. Not to say "That's stupid." The whole point of introducing IDE
> was to make drive installation simple and not require the user to know the
> details of the hardware, but they left this huge flaw in it?
leave it to them to assume the people will call them for "tech support"
that we'd pay them to answer questions ...
- some disks are worst than others in terms of ide support
and timeouts
> > put your 40GB on its own ide cable as Master.. make sure its 80-
> > conductor.. and that your bios supports it ( reports it as a 40GB drive )
>
> The BIOS handles it fine.
when you are running at speed ... you will see significant degradation
in signal on a 40 conductor vs 80 conductor ide cables...
-- dont bother using 40conductor cables
> > leave the working prev 1GB drive alone.. on its own cable
>
> I don't have four controllers here. I have four IDE drives and only two
> channels. Would it be effective to put each HDD on its own cable, with a
> CD drive as a slave?
if you mix different speed drives.. both dirves will work only as fast
as the slowest disk on your system
get another ide controller for $10 and put each disk of different
ata-speeds on different cables
- keep cdroms/dvd all by itself ...
> > and as posted earlier, make sure you have DMA enabled and -X at the right
> > speeds
>
> The earlier post didn't make it to me, I'll have to check the archive --
> thanks for mentioning it.
hdparm -d 1 -X 69 -c 3 -u1 /dev/hda
-- set dma ( -d 1 )
-- set ata speed ( -X69 == ata100 == udma5 )
"hdparm -iv | grep udma" will tell you your max udma speed it
supports
-- set u1 if you wanna go faster ( 5% or so ) over the course of a day
-- set io xfer speed ( -c 3 == 32bit i/o )
-- more options to play with
some options are supported by some drives/bios .. others are not
use the wrong set of options and you just rendered/scrambled your data on
the disk worthless ...
having a slow system due to adding a disk is equally bad as a scrambled
disk..... ( fix the problems that causing the symptoms )
-- dont mix drives unless they are both ata-100
and both have 2MB disk buffers .. etc.etc..
c ya
alvin
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