IRQ Problems

  • Thread starter Thread starter Fred Sturman
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Fred Sturman

I have an AT compatible computer with a Intel [email protected]
with 1,048,048KB of Ram. I am running Win2000Pro as a
standalone machine (dial-up only connection). The machine
has slowed and I found I have a potential IRQ issue.

The IRQ 9 is used by six different devices. Below is a
copy of the IRQs -

IRQ Device
9 MS ACPI-Compliant System
9 Radeon 7000 / Radeon VE video card
9 CNXT V92 Data Fax Voice modem
9 Standard Universal PCI to USB Host Controller
9 Standard Universal PCI to USB Host Controller
9 Avance AC'97 Audio for Intel Audio Controller
14 Primary IDE channel
15 Secondary IDE Channel
10 PCI Device
8 System CMOS/real time clock
13 Numeric data processor
6 Standard floppy disk controller
12 PS/2 Compatible Mouse
1 Standard 101/102 Key or MS Natural PS/2 keyboard
5 MPU-401 Compatible MIDI Device

The question: How can I assign different unused IRQ's to
stop the contention the system sees for IRQ 9?

Any help on this would be greatly appreciated.

Thanks, Fred
 
PCI IRQs in general are shareable, so it shouldn't
have much effect. But to change the IRQ, that's a
tough job with plug and pray systems.

Looks to me everything but the modem and the video
card is on the motherboard, so other than disabling them
(do you actually use both USB controllers?) you may
not be able to do much with them. You should be
able to move the modem to a different slot, but if the
video is AGP, you can't move that. Sometimes just
by moving PCI cards randomly around you can disturb
the PnP BIOS enough to come up with a reasonable
assignment.

Also, normally BIOSs have options on IRQ assignments
to slots (usually INTA, INTB, INTC, and INTD); or an
IRQ can be used for legacy ISA (you may not have this
with an all PCI system)
 
The only way to really fix this that I have discovered
works well but is practically a state secret (apparently
the Chairman decreed that documentation (as the term was
used when there was such a thing)is not to be shared:
1)Boot from the W200 CD (NOT the floppies; not the hard
disk)
2) Hit enter to install then IMMEDIATELY hit F5 when you
see "Windows is detecting..." (No response right away -
don't forget to also hit F6 when prompted if you have an
add-in IDE or SCSI controller that needs a driver so the
OS can find itself).
3) When the list of HALs appears, select Standard PC then
continue
4) When informed that W2K is already installed, select
repair this time
5) Complete the process BUT
6) During the reboot, go into the BIOS set up routine,(if
available, set ACPI to NO or OFF - probably not possible
on ATX MB, but older AT or AT/ATX MB like Tyan S1590S do
allow setting it off - not crucial to success);
select "Non PNP OS", "Reset config" YES, and assign a sane
set of IRQs to the various PCI/AGP slots and MB devices
(ports, HD primary & secondary, etc.)
NOTES: 1)Your BIOS likely is different than the three on
my current systems, but shld have similiar functions;
however, some BIOS set up routines (particularly on mass
market stuff, like the dreaded HP Pavilions) are designed
by, well, dummies for dummies, and you can't assign IRQs -
setting to non PNP OS may or may not suffice in that case.
2)This isn't idiot proof or foolproof - if you put an EIDE
controller and e.g., an Adaptec SCSI controller in PCI
slots that are hardwired (or firmwired) to share the same
IRQ, you probably won't even be able to boot your system
until you pull one or the other, do your penance, etc.
(been there). If you don't know which IRQs should be used
for which devices, per the conventions established by
people who ACTUALLY were smarter than us (as opposed to
erroneously thinking so, as some residents of Washington
State seem to do), this may not be a good thing for you to
do (For catching up, highly recommend Scott Mueller's
UPGRADING and REPAIRING PCs, currently in at least its
14th annual edition, huge book, expensive, last year's at
half price or used book store may be better bargain)
Likewise, if you assign IRQs to slots with cards that
can't or won't function with them, or cause other cards or
devices to be stuck with IRQs that affect them likewise,
you might end up worse off (hard as it is to imagine)
However, if you do know what you are doing, this takes a
major amount of headache and wasted time out of hardware
changes, vs the usual idiocacy where Windows assigns
everything to IRQ 9 or 3 and then complains and is
dysfunctional - I can actually change hardware around
(carefully and thoughtfully) and it USUALLY works the
first boot - which never happens in a loaded system on
ACPI, in my experience. Or if it does work, there is a
marked slowing due to the overhead of sorting out the IRQs
in the OS, a veritable deluge of Aliases in the device
mangler, etc. In my opinion, this ability to defeat
stupidity in the form of ACPI is the primary reason to put
up with all the other frailties and headaches of W2K vs a
well patched 98SE install.
STUCK IN THE MUD CUTTING CORNERS: it may be possible to
simply go into the device mangler and under Computer,
update driver for the ACPI HAL and choose the Standard PC
HAL (show all devices) - and thereby intentionally create
a BSOD, then do a sort of reinstall/repair (see Yegulap,
Windows Server Undocumented Solutions, which explains this
approach), but Microsoft's KB article (sorry, don't recall
the ## - there are several - try searching on NT and HAL)
says this will cause gloom and doom (although they say if
you aren't happy with the standard PC HAL, you can go back
to ACPI (go figure)). Roll the dice and see if this is
any more accurate than the advice the device mangler gives
you when it is too stupid to fix problems it created if
you like, but I took the approved path due to my aversion
to the dreaded BSOD.

As usual, I apologize for my verbosity, but this is such a
glorious solution that I have tried to give enough info to
allow successful resolution, which in the presence of an
ACPI HAL is, shall we say, sort of like the Yeti -
rumoured to exist, but no one any of us knows has ever
seen it.
Good luck, make a backup and pay all your bills first :\).
 
Fred Sturman said:
I have an AT compatible computer with a Intel [email protected]
with 1,048,048KB of Ram. I am running Win2000Pro as a
standalone machine (dial-up only connection). The machine
has slowed and I found I have a potential IRQ issue.

The IRQ 9 is used by six different devices. Below is a
copy of the IRQs -

IRQ Device
9 MS ACPI-Compliant System
9 Radeon 7000 / Radeon VE video card
9 CNXT V92 Data Fax Voice modem
9 Standard Universal PCI to USB Host Controller
9 Standard Universal PCI to USB Host Controller
9 Avance AC'97 Audio for Intel Audio Controller
14 Primary IDE channel
15 Secondary IDE Channel
10 PCI Device
8 System CMOS/real time clock
13 Numeric data processor
6 Standard floppy disk controller
12 PS/2 Compatible Mouse
1 Standard 101/102 Key or MS Natural PS/2 keyboard
5 MPU-401 Compatible MIDI Device

The question: How can I assign different unused IRQ's to
stop the contention the system sees for IRQ 9?

Any help on this would be greatly appreciated.

Thanks, Fred
Click to expand...

IF this is an IRQ 9 issue, then IF you are not using both serial ports (IRQ
4, 3) - COM1: and COM2: ...

I would move the modem card to IRQ 4 or 3 - to at least reduce the number of
shared devices on IRQ 9.

The sound cards are also another area that occasionally cause difficulties.
Is IRQ 11 empty?
 
How can slowing down be related to IRQ???
The only way to manually manage the resources is to have a Standard HAL.
 
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