APIC Mode??? What is that?

Candyman · Jul 6, 2002, 08:14 AM

I just got a new Abit KX7-333 motherboard and I see that there is a setting to enable/disable in the BIOS called APIC Mode. Does anyone know what that does? Should I enable it or disable it?

I hope the Abit dude is reading this....

sinjin · Jul 6, 2002, 08:55 AM

apic = advanced programmable interrupt controller or something to that effect...

i think it is for managing the interrupts on a multiprocessor system...but if you only have a single cpu enabling can improve performance.

Candyman · Jul 6, 2002, 08:58 AM

Quote:

Originally posted by sinjin
...but if you only have a single cpu enabling can improve performance.

Enabling will improve???? Is that a typo?

sinjin · Jul 6, 2002, 09:01 AM

yea i think so...it enables 24 lines of interrupt request lines rather than 16 (or something like that)...there has to be documentation on this somewhere...

sinjin · Jul 6, 2002, 09:07 AM

key benefits of I/O APIC

Candyman · Jul 6, 2002, 09:58 AM

I had it diabled by default.....however, when I enable it and save settings to reboot....nothing happens! Just a black screen. I go back to disable it and save/reboot and everything works again.....don't tell me I have to reformat to enable this setting...

sinjin · Jul 6, 2002, 10:14 AM

changing between enabled and disabled APIC mode may require you to reinstall Windows to allow a different hardware access layer to be used...

ajm786 · Jul 10, 2002, 12:35 PM

No, as far as I am concerened, you MUST re-install Windows. I've tried it before.

And as for me, I now always leave APIC on. You do get better performance and more IRQs.

shuki · Jul 16, 2002, 03:55 AM

not to be contradictory but I read twice to disable APIC. sorry don't have any links but just would recommend more info on the subject before reformatting....

ajm786 · Jul 16, 2002, 06:46 AM

You have to reformat either way, to avoid hosing your system.

Don't get confused with ACPI and APIC. ACPI is the standard for power saving, etc. etc. etc. implemented by Microsoft, which you will find in Windows. Go ahead. In you device manager, you will see that all your devices use one IRQ. THAT IS CALLED ACPI.

APIC is an option in your BIOS that stretches your IRQs from the standard AT of 15 to about 23 or 24, so that all your devices don't use one IRQ. THAT IS APIC.

shuki · Jul 16, 2002, 07:49 AM

Quote:

Originally posted by ajm786
Don't get confused with ACPI and APIC. ACPI is the standard for power saving, etc. etc. etc. implemented by Microsoft, which you will find in Windows. Go ahead. In you device manager, you will see that all your devices use one IRQ. THAT IS CALLED ACPI.

not to highjack the thread or anything

but how do you disable ACPI in windows?

shuki · Jul 16, 2002, 08:04 AM

n/m found out how here:
http://www.rage3d.com/board/showthre...eadid=33594824

also a bit of info on APIC in there too....

Gurm · Jul 17, 2002, 12:55 AM

Both ACPI _and_ APIC are good to have on. Don't disable either. Doing so only encourages the hardware manufacturers to make bad non-compliant hardware. You'll do TONS more work shuffling IRQ's (since despite APIC, in non-ACPI mode you only get 4 hardware-level interrupts - that's right ONLY 4!), and get almost no performance benefits. No matter what anyone told you, ACPI = GOOD.

- Gurm

misae · Jul 24, 2002, 06:27 AM

Quote:

Originally posted by Gurm
Both ACPI _and_ APIC are good to have on. Don't disable either. Doing so only encourages the hardware manufacturers to make bad non-compliant hardware. You'll do TONS more work shuffling IRQ's (since despite APIC, in non-ACPI mode you only get 4 hardware-level interrupts - that's right ONLY 4!), and get almost no performance benefits. No matter what anyone told you, ACPI = GOOD.

- Gurm

I agree with you on this one and by one hundred and fifty percent. Removing ACPI changes your OS kernel extensively and you may be left with a lot of features missing e.g. UDMA on your IDE drives etc because your IDE controller is trying to share the IRQ with your graphics card. (Well it did happen to me.. in fact I lost my 2ndary IDE altogether!... had to do a full format to fix it).

Once you disable ACPI from the BIOS and then the OS you cannot 'simply' turn it back on. Even with a system restore point set you may run into problems.

APIC though is slightly different as previously mentioned.

radTube · Jul 24, 2002, 07:50 AM

For some reason or another APIC made my system unstable. I did reistall windows after enabling it (actually I just enabled APIC right before I had to reinstall anyway), but had random lockouts afterwards. Everything's stable again now that I've disabled it. And I didn't have to reinstall Windows (XP) this time.

Ver · Jul 24, 2002, 04:47 PM

From my understaning, APIC is quite useless unless you have more than on cpu.

sjohnson · Jul 31, 2002, 10:25 AM

Quote:

Originally posted by Gurm...
Both ACPI _and_ APIC are good to have on. Don't disable either. Doing so only encourages the hardware manufacturers to make bad non-compliant hardware....

Um-hum - so I should trash-can my nVidia GF2 because it shares an interrupt with the LAN card in Win2k and I can't tell Win2k to assign it a unique IRQ when ACPI is enabled on a new install? I guess I can then take my chances on buying a new $400 nVidia card and hope that the drivers and hardware for this rather critical piece of hardware aren't "bad non-compliant" crashing and stuttering additions to my system?

Or, should I install as a Standard PC, spend 10 minutes assigning IRQ's and have a smooth running system with my existing GF2?

ACPI is the savior of MIS system integrators - makes installation and support a breeze. This is because, in a coporate environment any employee to tries to push their system with games or other 3D applications is rarely tolerated.

But for a gaming enthusiast, I can either spend beau-coup bux on the latest and greatest, then pray a LOT, and struggle with drivers and PCI slots and HOPE everything runs well when the system is stressed - or - Standard PC. Never say never and never say always

Jul 6, 2002, 08:14 AM	#1
Candyman [DH] Lover! Join Date: May 2002 Location: Toronto, Canada Posts: 284 Rep Power: 0	APIC Mode??? What is that? I just got a new Abit KX7-333 motherboard and I see that there is a setting to enable/disable in the BIOS called APIC Mode. Does anyone know what that does? Should I enable it or disable it? I hope the Abit dude is reading this.... __________________ AMD Athlon XP 1700+ @ 2.53GHz Abit NF7-S v.2 Thermalright SP-97 w/ TT Smart Fan 2 2 x 512MB GeIL PC3500 Platinum DDR 2 x 120GB WD HDD - RAID-0 2 x 80GB Barracuda V HDD - RAID-0 ATI Radeon AIW 9800PRO SB Audigy 2 HP L2335 23" LCD (DVI-D) WinXP Pro SP2

Jul 6, 2002, 08:55 AM	#2
sinjin the last samurai Join Date: May 2002 Posts: 1,086 Rep Power: 0	apic = advanced programmable interrupt controller or something to that effect... i think it is for managing the interrupts on a multiprocessor system...but if you only have a single cpu enabling can improve performance. __________________

Jul 6, 2002, 09:01 AM	#4
sinjin the last samurai Join Date: May 2002 Posts: 1,086 Rep Power: 0	yea i think so...it enables 24 lines of interrupt request lines rather than 16 (or something like that)...there has to be documentation on this somewhere... __________________

Jul 6, 2002, 09:07 AM	#5
sinjin the last samurai Join Date: May 2002 Posts: 1,086 Rep Power: 0	key benefits of I/O APIC __________________

Jul 6, 2002, 09:58 AM	Thread Starter #6
Candyman [DH] Lover! Join Date: May 2002 Location: Toronto, Canada Posts: 284 Rep Power: 0	I had it diabled by default.....however, when I enable it and save settings to reboot....nothing happens! Just a black screen. I go back to disable it and save/reboot and everything works again.....don't tell me I have to reformat to enable this setting... __________________ AMD Athlon XP 1700+ @ 2.53GHz Abit NF7-S v.2 Thermalright SP-97 w/ TT Smart Fan 2 2 x 512MB GeIL PC3500 Platinum DDR 2 x 120GB WD HDD - RAID-0 2 x 80GB Barracuda V HDD - RAID-0 ATI Radeon AIW 9800PRO SB Audigy 2 HP L2335 23" LCD (DVI-D) WinXP Pro SP2

Jul 6, 2002, 10:14 AM	#7
sinjin the last samurai Join Date: May 2002 Posts: 1,086 Rep Power: 0	changing between enabled and disabled APIC mode may require you to reinstall Windows to allow a different hardware access layer to be used... __________________

Jul 10, 2002, 12:35 PM	#8
ajm786 DriverHeaven Junior Member Join Date: May 2002 Posts: 32 Rep Power: 0	No, as far as I am concerened, you MUST re-install Windows. I've tried it before. And as for me, I now always leave APIC on. You do get better performance and more IRQs. __________________ That's right. BITE me. [color=#0000ff]Abit IC7 w/BIOS 24[/color] * [color=red]P4 2.6C @ 3.25 w/Zalman CNPS9000[/color] * 2GB (1GBx2) Samsung PC3200 ECC * WD5000KS and SP1614C; Toshiba SD-M1712; NEC ND-3550A * BFG 6800OC * Intel PRO/100+ LAN; Audigy 2 ZS Platinum; WinTV Go * Antec 480W TruePower in CoolerMaster ATCS 201-SX * Viewsonic VP201b and Hyundai L90D+ LCDs, and WinXP Pro/SP2 * Saitek Eclipse + Razer Copperhead PC/HT audio setup: Cambridge MC50 center, Athena AS-B1 mains, Megaworks 510D sub, Sonance Mariner 100 rear; connected to Onkyo TX-SR500 via 5.1 multichannel

Jul 16, 2002, 03:55 AM	#9
shuki DriverHeaven Senior Member Join Date: May 2002 Location: in the hidden place Posts: 1,975 Rep Power: 0	not to be contradictory but I read twice to disable APIC. sorry don't have any links but just would recommend more info on the subject before reformatting....

Jul 16, 2002, 06:46 AM	#10
ajm786 DriverHeaven Junior Member Join Date: May 2002 Posts: 32 Rep Power: 0	You have to reformat either way, to avoid hosing your system. Don't get confused with ACPI and APIC. ACPI is the standard for power saving, etc. etc. etc. implemented by Microsoft, which you will find in Windows. Go ahead. In you device manager, you will see that all your devices use one IRQ. THAT IS CALLED ACPI. APIC is an option in your BIOS that stretches your IRQs from the standard AT of 15 to about 23 or 24, so that all your devices don't use one IRQ. THAT IS APIC. __________________ That's right. BITE me. [color=#0000ff]Abit IC7 w/BIOS 24[/color] * [color=red]P4 2.6C @ 3.25 w/Zalman CNPS9000[/color] * 2GB (1GBx2) Samsung PC3200 ECC * WD5000KS and SP1614C; Toshiba SD-M1712; NEC ND-3550A * BFG 6800OC * Intel PRO/100+ LAN; Audigy 2 ZS Platinum; WinTV Go * Antec 480W TruePower in CoolerMaster ATCS 201-SX * Viewsonic VP201b and Hyundai L90D+ LCDs, and WinXP Pro/SP2 * Saitek Eclipse + Razer Copperhead PC/HT audio setup: Cambridge MC50 center, Athena AS-B1 mains, Megaworks 510D sub, Sonance Mariner 100 rear; connected to Onkyo TX-SR500 via 5.1 multichannel

Jul 16, 2002, 08:04 AM	#12
shuki DriverHeaven Senior Member Join Date: May 2002 Location: in the hidden place Posts: 1,975 Rep Power: 0	n/m found out how here: http://www.rage3d.com/board/showthre...eadid=33594824 also a bit of info on APIC in there too....

Jul 17, 2002, 12:55 AM	#13
Gurm Hail to the King, Baby! Join Date: Jun 2002 Location: This World AND The Next Posts: 193 Rep Power: 0	Both ACPI _and_ APIC are good to have on. Don't disable either. Doing so only encourages the hardware manufacturers to make bad non-compliant hardware. You'll do TONS more work shuffling IRQ's (since despite APIC, in non-ACPI mode you only get 4 hardware-level interrupts - that's right ONLY 4!), and get almost no performance benefits. No matter what anyone told you, ACPI = GOOD. - Gurm __________________ <Insert random "Army of Darkness" quote here...>

Jul 24, 2002, 07:50 AM	#15
radTube just keepin' it cool Join Date: May 2002 Location: Finland Posts: 228 Rep Power: 0	For some reason or another APIC made my system unstable. I did reistall windows after enabling it (actually I just enabled APIC right before I had to reinstall anyway), but had random lockouts afterwards. Everything's stable again now that I've disabled it. And I didn't have to reinstall Windows (XP) this time. __________________ [color=orange] [/color]

Jul 24, 2002, 04:47 PM	#16
Ver DriverHeaven Newbie Join Date: Jul 2002 Posts: 3 Rep Power: 0	From my understaning, APIC is quite useless unless you have more than on cpu.