hyoenmadan wrote:The i945 which OP has isn't your average 478 mobo. Also your never told which chipset were you using.
Also, your performance problem sounds more a Chipset/BIOS/Video/Driver problem than a ACPI matter.
I was using the i845 chipset. And your the first person I've heard refer to this scenario as a "performance problem." It's simply something other users and I did, back then to increase our performance in XP.
If you have a motherboard with a proper XP compliant ACPI implementation, ACPI will use APIC to assign higher IRQs to all integrated peripherals while reserving lower "PC-Legacy" ones for system devices and PCI cards. There aren't resource sharing on lower IRQs as you can see.
You don't seem to understand what is ACPI at all and you're confusing it with the ATX specification software power off feature.
http://wiki.osdev.org/ACPI
What you're saying could be completely true. But my understanding of ACPI really doesn't have anything to do with it. I'm simply describing what the effect of disabling ACPI was for my system, years ago. I got a performance boost, but lost the ability to hibernate/sleep and to cause the system to power itself down through software.
More importantly, your continued speculation on what "should" and "should not" be happening is not productive nor constructive. Plus, you'll notice that I never suggested that the OP should disable ACPI, I only asked if that is what he was referring to in the original post since I have mentioned it a few times, whereas I have not seen many people mention disabling AHCI. I only described my situation because you seemed to feel it was necessary to defend your opinion on disabling ACPI on a new system, which nobody suggested anyone should do. You prompted me to relate my experience, remember?
I don't know that anyone can even build a modern system with disabled ACPI since I believe XP SP1 was the last version of Windows which allowed it, and how new of a system can you make run on XP SP1? 🤣