# Just read about the APIC problem with NForce2>>

## LynZ

I have an Abit NF7-SL v2.0 .... 

After i flashed the newer bios and burned my videocard, my system began hanging up during the large DISK I/O operations.... sometimes t was the 1st gig, sometimes the 40th....but i hang

Is a APIC related here (enabled in kernel)

Or was my south bridge affected by my burned GeForce...?

I'm almost going to bring it to the servixce center that monday....

Can anyone help?

Has someone got a similar problem usng an nforce board?

Thx

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## LynZ

kernel 2.6.6-r1-gentoo

now 2.6.4-ck2

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## sdaffis

Still got problems with hangs? I use the following in my append= for boot with Abit NF7-s:

```
 append="apic_tack=2 idle=C1halt"
```

I use lilo but I guess it's kinda easy to add this to grub's config file?

Maybe I should add that I use both ACPI and APIC without any problems?  :Smile: 

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## Paranoid

The APIC problem doesn't occur with all nforce2 chipset boards. I can say from experience not to try using APIC with a A7N8X-D board  :Evil or Very Mad: 

Check out nforcershq forums or better yet, remove APIC support from the kernel and see if it still hangs.

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## LynZ

What's this APIC responsible for....

If i simply switch it off, will if affect the performance? Will this affect multitasking in linux? If not i guess i have no need to use it.

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## LynZ

And i guess this was my APIC..... cause when i turned it on once more and tryed to copy a hundred gigs it hung again....

Still want to know if this will affect my performance

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## sdaffis

```
$ cat /proc/interrupts 

           CPU0       

  0:  519571156          XT-PIC  timer

  1:     581509    IO-APIC-edge  i8042

  8:          2    IO-APIC-edge  rtc

  9:          0   IO-APIC-level  acpi

 12:   11592587    IO-APIC-edge  i8042

 14:    2890560    IO-APIC-edge  ide0

 15:       5300    IO-APIC-edge  ide1

 19:   47818983   IO-APIC-level  nvidia

 20:          0   IO-APIC-level  ehci_hcd

 21:    3455480   IO-APIC-level  ohci_hcd, NVidia nForce2

 22:   67432523   IO-APIC-level  eth0, ohci_hcd

NMI:          0 

LOC:  519469137 

ERR:          0

MIS:          1

jonas@XP2000 jonas $ 

```

This is what APIC (Advanced Programmable Interrupt Controller) does. It programs IRQs. Simple as that.  :Smile: 

I didn't use APIC before but can't say that it effects performance on my XP2000+ system. I just get a little more text during boot  :Smile: 

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## sdaffis

Since we have somewhat identical boards I think you can safely use APIC with ACPI with the code I appended in a former reply of mine. Just my $0.02!   :Smile: 

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## tactless

Well, more text during boot means a longer boot and bigger log files, so I guess it's a performance hit  :Laughing: 

As far as I know, if you turn off all of the SMP-related components of the kernel (which are known to cause a performance hit if you have only one processor), APIC doesn't even get compiled. So I'm guessing that APIC is related to SMP, and seeing as I only have one processor (and I don't know of any nForceII motherboards that support additional ones) - I probably don't need it.

Am I wrong about this?

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## LynZ

I think Nforce II doen't support multiple processors = don't need APIC...

Thx 2 all......

[Off] Just passed the Mathematical Analys exam =)))))) in MIPT

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## sdaffis

 *Quote:*   

> Well, more text during boot means a longer boot and bigger log files, so I guess it's a performance hit
> 
> As far as I know, if you turn off all of the SMP-related components of the kernel (which are known to cause a performance hit if you have only one processor), APIC doesn't even get compiled. So I'm guessing that APIC is related to SMP, and seeing as I only have one processor (and I don't know of any nForceII motherboards that support additional ones) - I probably don't need it.
> 
> Am I wrong about this?

  Everything that I've encountered with APIC is in no way directly related to SMP. It's just a better  :Question:  way to program the interrupt table (IRQ table). Works fine for me, as stated before  :Smile: 

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## Plastic

It's all fixed in 2.6.6 and later (the patch went mainstream). You don't even need to append and options to the kernel line.

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## sdaffis

Is that so? Man, I feel stupid!  :Very Happy: 

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## rush_ad

i seem to have the same problem running nforce3 and kernel 2.6.10 and later. so whats the solution?

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## immure

I had this problem, changed to the vanilla-sources, and took acpi and apic out of the kernel. After this everything was fine. 

I haven't noticed any performance hits at all, only thing is having to press the power button to turn off my computer :S

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## rush_ad

i have the same problem on my other machine running ubuntu, any solution for that?

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## NeddySeagoon

rush_ad,

Try adding noapic to the kerenl command line in grub.

Theres lots of useful kernel parameters. Read /usr/src/linux/Documentation/kernel-parameters.txt for some.

Other files are referenced from there.

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## rush_ad

i have tries noapic and apic=off options with no luck. still the same problem. 

i tried ubuntu live-cd and even that froze my computer.

well, i installed different OS many times. tried suse92 suse93 ubuntu kubuntu and they all install fine. computer never hangs while installing. its crashes only when i am running it after installing.

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## rush_ad

so anybody figured out anythign yet?

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