Arch Linux

Pechorin

Member

From: Belgrade

Registered: 2004-12-23

Posts: 28

Website

Realtek ethernet slows down computer

First of all, I'm sorry if I'm posting in the wrong category, but nevertheless:

I have just purchased a new PC, dualcore with a K9N Neo-F motherboard with nForce 520 on it. However, the problem is:

when I use the ethernet card (on board realtek, loads module r8169) to fetch stuff from the Internet everything else slows down. E.g. if I'm wget'ing something, it will take forever for firefox to load or gedit to open - everything gets sluggish while I'm downloading/uploading. I tried disabling that LAN and inserted another PCI ethernet card, still the same

I checked the usual suspects: there seems to be no obvious IRQ conflict as far as I can tell (granted, I only checked /proc/interrupts which gives " 20: 14 7936   IO-APIC-fasteoi eth0" and nothing else on IRQ 20. I get the same thing for two different PCI slots and onboard LAN). I tried booting with "noapic acpi=off" options, but still no difference.

I disabled ipv6.

Also, dmesg gives me this, I can't interpret it:

ACPI: PCI Interrupt Link [LAZA] enabled at IRQ 20
ACPI: PCI Interrupt 0000:01:0a.0[A] -> Link [LNKC] -> GSI 19 (level, low) -> IRQ 20
eth0: RealTek RTL8139 at 0xf89bcc00, 00:40:05:34:4f:af, IRQ 20

What am I missing?

Last edited by Pechorin (2007-09-15 17:55:00)

robertp

Member

From: Warszawa, Poland

Registered: 2007-09-11

Posts: 123

Re: Realtek ethernet slows down computer

Shouldn't you load  8139too module instead of r8169?

Pechorin

Member

From: Belgrade

Registered: 2004-12-23

Posts: 28

Website

Re: Realtek ethernet slows down computer

Robert,

Yes, I did load 8139too when I used a 8139 realtek card. I tried both r8169 (kernel, automatically loaded) and r8168 (from realtek's site) for the other onboard lan (rtl8111b).

Pechorin

Member

From: Belgrade

Registered: 2004-12-23

Posts: 28

Website

Re: Realtek ethernet slows down computer

Alright, another thing I noticed: the slower the connection (e.g. when I throttle the download), the more responsive other applications are. So, it's probably not interrupts, though I'm not sure.

ralvez

Member

From: Canada

Registered: 2005-12-06

Posts: 1,718

Website

Re: Realtek ethernet slows down computer

If I understand you are loading both modules, correct?
On load what is required by the card as the modules may be "fighting" each other and causing the machine to slow down.

R.

p.s. if one of the modules is auto-loaded black list it to prevent it from happening.

Last edited by ralvez (2007-09-16 18:49:44)

Pechorin

Member

From: Belgrade

Registered: 2004-12-23

Posts: 28

Website

Re: Realtek ethernet slows down computer

ralvez, nope, I'm loading one module at the time. I made sure the other module was unloaded before using the new device. So, I tried two different ethernet cards. I tried the first one with r8169 and r8168 from realtek (and it works the same with both modules), and the second one I tried with 8139too (and it behaves exactly the same like the first ethernet card). I doubt there is the same bug in all drivers so my best guess is that it has to be something else.

ralvez

Member

From: Canada

Registered: 2005-12-06

Posts: 1,718

Website

Re: Realtek ethernet slows down computer

Fair enough.
Try the mii-tool (as root) see it you can get some information.
Also, are you using the card via dhcp or static IP. If you can set the card as static and see if you can find any differences.
Do you have set your DNS servers properly? That can cause a lot of troubles and slow downs if is not correct.

Hope this helps.

R.

Pechorin

Member

From: Belgrade

Registered: 2004-12-23

Posts: 28

Website

Re: Realtek ethernet slows down computer

Ralvez, first of all, thanks for the help.

mii-tool gives me "eth0: negotiated 100baseTx-FD flow-control, link ok" and that's it. I tried going with static IP, but that didn't help either. I double checked DNS servers, they seem fine. Meanwhile, I tried both x64 and 32-bit Archlinux, always the same.