Vista - Vista IRQ management

My Vista resources map shows the below 3 internal devices on my Platinum P6N
SLI Platinum motherboard with an E6600 Core Duo Intel CPU sharing the same
IRQ "(PCI) 20". I have nothing plugged into any PCI slots. One graphics
adapter in the PCIe x16 slot.

- High Definition Audio Controller
- NVIDIA nForce 430/410 SATA Controller
- Standard OpenHCD USB Host controller

Why is this? Does it not matter anymore to share an IRQ rather than have a
dedicated IRQ? Why would PnP or ACPI or whomever not spread the IRQ's out
more?

I've also got a whole lot of IRQ's showing "(ISA) xx Microsoft
ACPI-Compliant System" which I'm guessing are unused IRQs.

I even have a couple IRQs showing (PCI) -2, -3 and -4 and don't understand
why some would be negative or why some are ISA and others PCI.

Where can I learn more about this and is this an issue?

Thanks,
Dave

P.S. I have cross posted this to general and hardware_devices.

Hi Dave,

IRQ 20 is a virtual IRQ created by the system to handle those devices, and
IRQ sharing has been the norm since Win98. While those particular devices
may be onboard, they still are on the PCI bus, which is why it shows that
designation. A negative number may result when the first bit is a 1 rather
than 0, the system is interpreting it as a signed number rather than
unsigned large number. Many virtual interrupt requests can be created to
handle the various pieces of hardware's demand for the cpu's attention. I
would only be concerned if system information shows a resource conflict.

--
Best of Luck,

Rick Rogers, aka "Nutcase" - Microsoft MVP
http://mvp.support.microsoft.com/
Windows help - www.rickrogers.org
My thoughts http://rick-mvp.blogspot.com

"Dave" <REMOVETHISDaveAtHome@earthlink.net> wrote in message
news:eDJwj65hHHA.4032@TK2MSFTNGP02.phx.gbl...
> My Vista resources map shows the below 3 internal devices on my Platinum
> P6N SLI Platinum motherboard with an E6600 Core Duo Intel CPU sharing the
> same IRQ "(PCI) 20". I have nothing plugged into any PCI slots. One
> graphics adapter in the PCIe x16 slot.
>
> - High Definition Audio Controller
> - NVIDIA nForce 430/410 SATA Controller
> - Standard OpenHCD USB Host controller
>
> Why is this? Does it not matter anymore to share an IRQ rather than have a
> dedicated IRQ? Why would PnP or ACPI or whomever not spread the IRQ's out
> more?
>
> I've also got a whole lot of IRQ's showing "(ISA) xx Microsoft
> ACPI-Compliant System" which I'm guessing are unused IRQs.
>
> I even have a couple IRQs showing (PCI) -2, -3 and -4 and don't understand
> why some would be negative or why some are ISA and others PCI.
>
> Where can I learn more about this and is this an issue?
>
> Thanks,
> Dave
>
> P.S. I have cross posted this to general and hardware_devices.
>

OK thanks. Perhaps does not matter with the newer integrated APIC rather
than the old cascaded PIC chips that could only do 15 interrupts total and
had to share. Still curious about what the ISA vs. PCI status really means
underneath. I show no conflicts but just thought it would be more efficient
for devices to have their own IRQ whether physical or virtual rather than
share.

I found this article
http://www.e-articles.info/e/a/title...CI-interrupts/
but it does not currently work as their database appears down.

Thanks,
Dave

"Rick Rogers" <rick@mvps.org> wrote in message
news:e$QlyM6hHHA.1048@TK2MSFTNGP04.phx.gbl...
> Hi Dave,
>
> IRQ 20 is a virtual IRQ created by the system to handle those devices, and
> IRQ sharing has been the norm since Win98. While those particular devices
> may be onboard, they still are on the PCI bus, which is why it shows that
> designation. A negative number may result when the first bit is a 1 rather
> than 0, the system is interpreting it as a signed number rather than
> unsigned large number. Many virtual interrupt requests can be created to
> handle the various pieces of hardware's demand for the cpu's attention. I
> would only be concerned if system information shows a resource conflict.
>
> --
> Best of Luck,
>
> Rick Rogers, aka "Nutcase" - Microsoft MVP
> http://mvp.support.microsoft.com/
> Windows help - www.rickrogers.org
> My thoughts http://rick-mvp.blogspot.com
>
> "Dave" <REMOVETHISDaveAtHome@earthlink.net> wrote in message
> news:eDJwj65hHHA.4032@TK2MSFTNGP02.phx.gbl...
>> My Vista resources map shows the below 3 internal devices on my Platinum
>> P6N SLI Platinum motherboard with an E6600 Core Duo Intel CPU sharing the
>> same IRQ "(PCI) 20". I have nothing plugged into any PCI slots. One
>> graphics adapter in the PCIe x16 slot.
>>
>> - High Definition Audio Controller
>> - NVIDIA nForce 430/410 SATA Controller
>> - Standard OpenHCD USB Host controller
>>
>> Why is this? Does it not matter anymore to share an IRQ rather than have
>> a dedicated IRQ? Why would PnP or ACPI or whomever not spread the IRQ's
>> out more?
>>
>> I've also got a whole lot of IRQ's showing "(ISA) xx Microsoft
>> ACPI-Compliant System" which I'm guessing are unused IRQs.
>>
>> I even have a couple IRQs showing (PCI) -2, -3 and -4 and don't
>> understand why some would be negative or why some are ISA and others PCI.
>>
>> Where can I learn more about this and is this an issue?
>>
>> Thanks,
>> Dave
>>
>> P.S. I have cross posted this to general and hardware_devices.
>>
>

Nevermind that article. It is talking about the real ISA and PCI boards from
way back. Makes me even more curious though why they still classify current
IRQs in that fashion...Dave

"Dave" <REMOVETHISDaveAtHome@earthlink.net> wrote in message
news:%23xJkVS6hHHA.392@TK2MSFTNGP06.phx.gbl...
> OK thanks. Perhaps does not matter with the newer integrated APIC rather
> than the old cascaded PIC chips that could only do 15 interrupts total and
> had to share. Still curious about what the ISA vs. PCI status really means
> underneath. I show no conflicts but just thought it would be more
> efficient for devices to have their own IRQ whether physical or virtual
> rather than share.
>
> I found this article
> http://www.e-articles.info/e/a/title...CI-interrupts/
> but it does not currently work as their database appears down.
>
> Thanks,
> Dave
>
> "Rick Rogers" <rick@mvps.org> wrote in message
> news:e$QlyM6hHHA.1048@TK2MSFTNGP04.phx.gbl...
>> Hi Dave,
>>
>> IRQ 20 is a virtual IRQ created by the system to handle those devices,
>> and IRQ sharing has been the norm since Win98. While those particular
>> devices may be onboard, they still are on the PCI bus, which is why it
>> shows that designation. A negative number may result when the first bit
>> is a 1 rather than 0, the system is interpreting it as a signed number
>> rather than unsigned large number. Many virtual interrupt requests can be
>> created to handle the various pieces of hardware's demand for the cpu's
>> attention. I would only be concerned if system information shows a
>> resource conflict.
>>
>> --
>> Best of Luck,
>>
>> Rick Rogers, aka "Nutcase" - Microsoft MVP
>> http://mvp.support.microsoft.com/
>> Windows help - www.rickrogers.org
>> My thoughts http://rick-mvp.blogspot.com
>>
>> "Dave" <REMOVETHISDaveAtHome@earthlink.net> wrote in message
>> news:eDJwj65hHHA.4032@TK2MSFTNGP02.phx.gbl...
>>> My Vista resources map shows the below 3 internal devices on my Platinum
>>> P6N SLI Platinum motherboard with an E6600 Core Duo Intel CPU sharing
>>> the same IRQ "(PCI) 20". I have nothing plugged into any PCI slots. One
>>> graphics adapter in the PCIe x16 slot.
>>>
>>> - High Definition Audio Controller
>>> - NVIDIA nForce 430/410 SATA Controller
>>> - Standard OpenHCD USB Host controller
>>>
>>> Why is this? Does it not matter anymore to share an IRQ rather than have
>>> a dedicated IRQ? Why would PnP or ACPI or whomever not spread the IRQ's
>>> out more?
>>>
>>> I've also got a whole lot of IRQ's showing "(ISA) xx Microsoft
>>> ACPI-Compliant System" which I'm guessing are unused IRQs.
>>>
>>> I even have a couple IRQs showing (PCI) -2, -3 and -4 and don't
>>> understand why some would be negative or why some are ISA and others
>>> PCI.
>>>
>>> Where can I learn more about this and is this an issue?
>>>
>>> Thanks,
>>> Dave
>>>
>>> P.S. I have cross posted this to general and hardware_devices.
>>>
>>
>
>

Hi Dave,

Not 100% on this, but I think that it shows that legacy designation because
of the range of the addresses used, not because it's actually an ISA device.
If you run msinfo32 and look at the hardware resources, you'll see that the
designation does not carry over here.

--
Best of Luck,

Rick Rogers, aka "Nutcase" - Microsoft MVP
http://mvp.support.microsoft.com/
Windows help - www.rickrogers.org
My thoughts http://rick-mvp.blogspot.com

"Dave" <REMOVETHISDaveAtHome@earthlink.net> wrote in message
news:evsaVc6hHHA.4516@TK2MSFTNGP03.phx.gbl...
> Nevermind that article. It is talking about the real ISA and PCI boards
> from way back. Makes me even more curious though why they still classify
> current IRQs in that fashion...Dave
>
> "Dave" <REMOVETHISDaveAtHome@earthlink.net> wrote in message
> news:%23xJkVS6hHHA.392@TK2MSFTNGP06.phx.gbl...
>> OK thanks. Perhaps does not matter with the newer integrated APIC rather
>> than the old cascaded PIC chips that could only do 15 interrupts total
>> and had to share. Still curious about what the ISA vs. PCI status really
>> means underneath. I show no conflicts but just thought it would be more
>> efficient for devices to have their own IRQ whether physical or virtual
>> rather than share.
>>
>> I found this article
>> http://www.e-articles.info/e/a/title...CI-interrupts/
>> but it does not currently work as their database appears down.
>>
>> Thanks,
>> Dave
>>
>> "Rick Rogers" <rick@mvps.org> wrote in message
>> news:e$QlyM6hHHA.1048@TK2MSFTNGP04.phx.gbl...
>>> Hi Dave,
>>>
>>> IRQ 20 is a virtual IRQ created by the system to handle those devices,
>>> and IRQ sharing has been the norm since Win98. While those particular
>>> devices may be onboard, they still are on the PCI bus, which is why it
>>> shows that designation. A negative number may result when the first bit
>>> is a 1 rather than 0, the system is interpreting it as a signed number
>>> rather than unsigned large number. Many virtual interrupt requests can
>>> be created to handle the various pieces of hardware's demand for the
>>> cpu's attention. I would only be concerned if system information shows a
>>> resource conflict.
>>>
>>> --
>>> Best of Luck,
>>>
>>> Rick Rogers, aka "Nutcase" - Microsoft MVP
>>> http://mvp.support.microsoft.com/
>>> Windows help - www.rickrogers.org
>>> My thoughts http://rick-mvp.blogspot.com
>>>
>>> "Dave" <REMOVETHISDaveAtHome@earthlink.net> wrote in message
>>> news:eDJwj65hHHA.4032@TK2MSFTNGP02.phx.gbl...
>>>> My Vista resources map shows the below 3 internal devices on my
>>>> Platinum P6N SLI Platinum motherboard with an E6600 Core Duo Intel CPU
>>>> sharing the same IRQ "(PCI) 20". I have nothing plugged into any PCI
>>>> slots. One graphics adapter in the PCIe x16 slot.
>>>>
>>>> - High Definition Audio Controller
>>>> - NVIDIA nForce 430/410 SATA Controller
>>>> - Standard OpenHCD USB Host controller
>>>>
>>>> Why is this? Does it not matter anymore to share an IRQ rather than
>>>> have a dedicated IRQ? Why would PnP or ACPI or whomever not spread the
>>>> IRQ's out more?
>>>>
>>>> I've also got a whole lot of IRQ's showing "(ISA) xx Microsoft
>>>> ACPI-Compliant System" which I'm guessing are unused IRQs.
>>>>
>>>> I even have a couple IRQs showing (PCI) -2, -3 and -4 and don't
>>>> understand why some would be negative or why some are ISA and others
>>>> PCI.
>>>>
>>>> Where can I learn more about this and is this an issue?
>>>>
>>>> Thanks,
>>>> Dave
>>>>
>>>> P.S. I have cross posted this to general and hardware_devices.
>>>>
>>>
>>
>>
>
>

I remember this issue coming up back in the days of NT4. Apparently it's by
design, and actually helps speed things up a bit.

All the advice back then was to leave well alone. It ain't broke, so
there's no need to fix anything.

Steve