Running ATA-100 on two drives, XP SP2

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C

CS

I have a Compaq Presario 7000 desktop, 1.4G Athlon processor, 512 meg ram,
XP SP2. System supports ATA-100. I have two Seagate EIDE drives, ATA-100,
installed using cable select. Whenever the two drives are on the primary
IDE channel (running off the same cable on the MB), the system drops the I/O
speed to ATA-66 (Mode 4). Whenever one drive (boot drive) is attached by
itself on primary IDE or the second drive (non-boot) is attached to the
secondary IDE channel (along with the DVD drive), the first drive will run
ATA-100 (Mode 5). However, even with the second drive running on the second
IDE channel, the drive will only run Mode 4. First drive is 250 gig
ST3250823A, second drive is 300 gig ST3300831A.

I've tried uninstalling the primary IDE channel under device manager and
rebooting, and also tried the registry edits at:
http://support.microsoft.com/default.aspx?scid=kb;en-us;817472

which change the way XP deals with CRC errors, but no luck. Also edited the
registry to set the devices to Mode 5, but, on boot, they both drop back to
Mode 4.

Other than running the second drive on the secondary channel (and living
with Mode 4 operation on it), does anyone have any ideas how to remedy this
issue? I would like to run both drives in Mode 5, either on the primary IDE
or split between the primary and secondary IDE channels. But is seems that,
for some reason, my second drive cannot run Mode 5. Maybe there is some way
to force the drive into Mode 5 or bypass XP's control over the I/O speed?

thanks in advance
 
CS said:
I have a Compaq Presario 7000 desktop, 1.4G Athlon processor, 512 meg ram,
XP SP2. System supports ATA-100. I have two Seagate EIDE drives, ATA-100,
installed using cable select. Whenever the two drives are on the primary
IDE channel (running off the same cable on the MB), the system drops the
I/O speed to ATA-66 (Mode 4). Whenever one drive (boot drive) is attached
by itself on primary IDE or the second drive (non-boot) is attached to the
secondary IDE channel (along with the DVD drive), the first drive will run
ATA-100 (Mode 5). However, even with the second drive running on the
second IDE channel, the drive will only run Mode 4. First drive is 250 gig
ST3250823A, second drive is 300 gig ST3300831A.

I've tried uninstalling the primary IDE channel under device manager and
rebooting, and also tried the registry edits at:
http://support.microsoft.com/default.aspx?scid=kb;en-us;817472

which change the way XP deals with CRC errors, but no luck. Also edited
the registry to set the devices to Mode 5, but, on boot, they both drop
back to Mode 4.

Other than running the second drive on the secondary channel (and living
with Mode 4 operation on it), does anyone have any ideas how to remedy
this issue? I would like to run both drives in Mode 5, either on the
primary IDE or split between the primary and secondary IDE channels. But
is seems that, for some reason, my second drive cannot run Mode 5. Maybe
there is some way to force the drive into Mode 5 or bypass XP's control
over the I/O speed?

thanks in advance
Click to expand...
Checked them both in the BIOS ?. Auto or assigned ?.
bw..OJ
 
CS said:
I have a Compaq Presario 7000 desktop, 1.4G Athlon processor, 512 meg ram,
XP SP2. System supports ATA-100. I have two Seagate EIDE drives, ATA-100,
installed using cable select. Whenever the two drives are on the primary
IDE channel (running off the same cable on the MB), the system drops the
I/O speed to ATA-66 (Mode 4). Whenever one drive (boot drive) is attached
by itself on primary IDE or the second drive (non-boot) is attached to the
secondary IDE channel (along with the DVD drive), the first drive will run
ATA-100 (Mode 5). However, even with the second drive running on the
second IDE channel, the drive will only run Mode 4. First drive is 250 gig
ST3250823A, second drive is 300 gig ST3300831A.

I've tried uninstalling the primary IDE channel under device manager and
rebooting, and also tried the registry edits at:
http://support.microsoft.com/default.aspx?scid=kb;en-us;817472

which change the way XP deals with CRC errors, but no luck. Also edited
the registry to set the devices to Mode 5, but, on boot, they both drop
back to Mode 4.

Other than running the second drive on the secondary channel (and living
with Mode 4 operation on it), does anyone have any ideas how to remedy
this issue? I would like to run both drives in Mode 5, either on the
primary IDE or split between the primary and secondary IDE channels. But
is seems that, for some reason, my second drive cannot run Mode 5. Maybe
there is some way to force the drive into Mode 5 or bypass XP's control
over the I/O speed?

thanks in advance
Click to expand...

Following up on my own post, after some searching found an entry on an
downrev BIOS flash for this PC that says the following:

"If an ATA 100 drive shares a cable with any other drive, slows it down to
ATA 66 to prevent theoretical loss of data integrity."

So I guess my issue is in the BIOS. Anyway, I now run my main drive by
itself (ATA 100) and my backup on the secondary IDE with the DVD drive (at
ATA 66).
 
CS said:
Following up on my own post, after some searching found an entry on an
downrev BIOS flash for this PC that says the following:

"If an ATA 100 drive shares a cable with any other drive, slows it down to
ATA 66 to prevent theoretical loss of data integrity."
Click to expand...

That means that it is broken by design.
Time to give the MoBo back for lack of revealing hidden defects.
Fot laughs you can try to disable the second channel in bios and
see if that makes a difference to the second HD in Windows.
 
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