Win2k hal: ACPI vs. MPS (for SMP system)

[Sir Fredrick]

Anyone know what the differences between ACPI and MPS are? I just switched over to see if it was any different, and the only thing I really noticed was that now instead of Win2k putting multiple devices on the same IRQ, it uses at least 129 IRQs and puts everything on it's own IRQ:

0 -- System Timer
1 -- Keyboard
3 -- Com2
4 -- Com1
5 -- ISA Winmodem
6 -- Floppy Controller
8 -- Real time clock
12 -- Logitech mouse
13 -- Numeric data processor
19 -- Intel PCI to USB controller
36 -- Adaptec 29160 SCSI card
40 -- Philips Acoustic Edge
48 -- Realtek NIC
128-- Nvidia Riva TNT

I'd really like to get the Philips Acoustic Edge on a "normal" IRQ, but there doesn't seem to be any way to do this on my system, disabling PNP OS in the BIOS doesn't phase Win2k.

 

[obenton]

Two different things. ACPI is HAL that uses ACPI power management (very much worthwhile, if all your hardware supports it). MPS provides support for dual processors. You can combine them, using both. My wife's computer is ACPI MPS. Caveat: to switch between an ACPI and non-ACPI configuration requires a repair install. To switch between MPS and non-MPS can be done in Control Panel.

 

[Sir Fredrick]

I was on "ACPI Multiprocessor", but I switched the HAL to "MPS Multiprocessor" instead. I don't use any of the ACPI power management features, so that doesn't matter. I was really hoping to get Win2k to use "normal" IRQs. Any way to do this with a multiprocessor system?

 

[obenton]

w2k applies its own virtual IRQs, no matter what HAL you use, with no option to change (except for some ISA devices). If the hardware's w2k compatible, it works. If not, you've got to change to compatible hardware. I've noticed posts about the Philips device's w2k compatiblity, if that's what you're having problems with. Maybe someone posted a fix - I don't know, since I never read them.

 

[PliotronX]

I just wanted to add that the "PnP OS installed" option in the BIOS affects only ISA devices 🙂

Also, I've never seen any "virtual IRQs" applied under Win2k.. are virtual IRQs good or bad?

 

[obenton]

My take on it is that they're called "virtual" because they don't exist in any real sense. Win2k has its own way of handling and signaling devices (as long as they're w2k compatible), different from operating systems that use conventional, "real" IRQ signaling lines. I don't believe the IRQ numbers that we see in w2k's device manager mean very much, since there's nothing we can do to or with them except gaze at them, and are put there, perhaps, to make, us, the users, feel more comfortable - make us backwards compatible, so to speak. Perhaps the assigned number relates to w2k's internal device signaling method. No doubt there are MS KB articles that describe it in detail, or some knowledgeable person will enlighten us. Overall, it's certainly a plus. Remember the old days when, in order to add a new device, we had to scrounge around and manipulate (or take something else out) in order to free up an IRQ?

 

[PliotronX]

Ah I see, thanks for clearing that up 🙂

 

[GAZZA]

tnx for the info obenton

 

[Noriaki]

<< Also, I've never seen any &quot;virtual IRQs&quot; applied under Win2k.. are virtual IRQs good or bad? >>

Sure you have 🙂 :


<<
19 -- Intel PCI to USB controller
36 -- Adaptec 29160 SCSI card
40 -- Philips Acoustic Edge
48 -- Realtek NIC
128-- Nvidia Riva TNT
>>



Those are all Virtual IRQs. Like obenton said, they don't really exsist. The only IRQ channels defined in the x86 architecture are 0-7 and 8-15 (there is a distinct different in the two groups, that's why I split them, though you probably don't give a damn, in moderm systems all 16 behave exactly the same), so anything beyond 0-15 are virutal IRQs.

If you care Win2k supports 240 virtual IRQs (IRQ number 0-255, with 0-15 being &quot;real&quot😉 of them. As obenton said, as long as the device is Win2k compliant, it makes no difference if it gets a Real IRQ or a Virtual one. The only problem I've ever had is with an old DOS game, it expects your sound card at Memory Port 0x220, and on IRQ 5 or 7. So I had to run without sound 🙁 Oh well it's not like I ever play the game anymore, I just wanted to see if it would work.