R
Rog.
I have what is a simple question, though I have been unable to find an answer
as yet; the question is in 2 parts:
1/ How do I tell Vista that I want to change the IRQs that Vista chooses to
assign to hardware devices?
2/ How do I tell Vista in what priority order I want these IRQs handled?
Strictly the second part is not needed if you can change all the IRQs (and
you know their fixed priority order), but it would be useful.
The PC in question is a modern device with both ACPI and APIC, using only
PCI devices (the COM/PARALLEL devices on the legacy bus are turned off).
This means there are 24 available IRQs - far more than there are devices
needing them.
Unfortunately the Vista resource broker lamely decides to share just a few
IRQs between the most resource intensive devices. Although all the devices
are CAPABLE of sharing IRQs, this does not mean that sharing is DESIRABLE.
For example, the sound chip shares an IRQ with the main hard disk. Given
that Vista has reduced the audio buffering available to better support
realtime music, making it share an IRQ with a resource-intensive device like
a disk or network card leads to appaling sound breakup - not very helpful.
Similarly, the USB bus and 1394 bus have Isochronous modes which can/will
fail if forced to share IRQs with inappropriate resources.
Just to avoid wasting anyone's time, these resources cannot be changed by
switching slots (they are all on the motherboard), nor can they be changed in
the bios. The Vista HAL happily assigns resources using its poorly thought
out algorithms, and as there are no conflicts, the device manager does not
allow any changes.
I'm fairly sure these IRQ changes SHOULD be possible; it's just a question
of whether Microsoft are restricting this information, or whether they have
been drinking their own cool-aid too much and not put this manual adjustment
capability in.
Anyone have any clues where I might look?
Rog.
as yet; the question is in 2 parts:
1/ How do I tell Vista that I want to change the IRQs that Vista chooses to
assign to hardware devices?
2/ How do I tell Vista in what priority order I want these IRQs handled?
Strictly the second part is not needed if you can change all the IRQs (and
you know their fixed priority order), but it would be useful.
The PC in question is a modern device with both ACPI and APIC, using only
PCI devices (the COM/PARALLEL devices on the legacy bus are turned off).
This means there are 24 available IRQs - far more than there are devices
needing them.
Unfortunately the Vista resource broker lamely decides to share just a few
IRQs between the most resource intensive devices. Although all the devices
are CAPABLE of sharing IRQs, this does not mean that sharing is DESIRABLE.
For example, the sound chip shares an IRQ with the main hard disk. Given
that Vista has reduced the audio buffering available to better support
realtime music, making it share an IRQ with a resource-intensive device like
a disk or network card leads to appaling sound breakup - not very helpful.
Similarly, the USB bus and 1394 bus have Isochronous modes which can/will
fail if forced to share IRQs with inappropriate resources.
Just to avoid wasting anyone's time, these resources cannot be changed by
switching slots (they are all on the motherboard), nor can they be changed in
the bios. The Vista HAL happily assigns resources using its poorly thought
out algorithms, and as there are no conflicts, the device manager does not
allow any changes.
I'm fairly sure these IRQ changes SHOULD be possible; it's just a question
of whether Microsoft are restricting this information, or whether they have
been drinking their own cool-aid too much and not put this manual adjustment
capability in.
Anyone have any clues where I might look?
Rog.
