athlon-xp + nforce2 + kernel 2.6.x performance woes - SOLVED

nabla · Last edited by nabla on Tue Jun 08, 2004 9:07 am; edited 2 times in total

hi all,

today i've detected the strangest linux behaviour of my life:

hardware: athlon-xp 2800+, nforce2 on a7n8x

expected "openssl speed rsa"-performance: about 19'000 verfies/s on 512 bits.

windows xp: ~19700 verifies/s
gentoo-live-cd 2004.0: ~19500 verifies/s
gentoo-live-cd chrooted to my system (using my openssl-build): ~19500 verifies/s
my system (2.6.3 or 2.6.6): ~13000 verifies/s

this slowness also occurs on compiling etc...

my kernel is really small, no debug or so. dmesg looks clean and safe.
no applications running, top shows 97% idle. (when testing not even X running).

tried 2.6.3 to 2.6.6 kernels, gentoo-dev or vanilla without any success.

has somebody an idea where the problem may be? whats the performance of other athlon xp + nforce2 users?

thanks a lot for any hints,

cu nabla

B@rtW@re · n00b Joined: 07 Jun 2004 Posts: 29

i had the same problem with nforce2, it was related to dma (yes it can slow your system down, even when you are doing nothing) you have to compile the amd and nvidia ide module in your device driver sector. first i was looking for an nvidia ide driver but couldn't find it because amd stands in front of it

nabla · Posted: Mon Jun 07, 2004 8:37 pm Post subject:

no, dma can't be the point...
i have the modules you mentioned and hdparm -tT on my harddisks gives nice and fast results... (~500MB/s, ~55 MB/s).

but thank you anyway.

any further ideas?

fca · Guru Joined: 22 Feb 2003 Posts: 346 Location: Netherlands

I have an nForce 2 with an Athlon 2400+ and kernel 2.6.6-mm1, with X running, I get the following figure:

nabla · Posted: Tue Jun 08, 2004 6:54 am Post subject:

yeah, you are running at the expected speed!

i'will try the mm-sources later that day, thanks for the hint.

nabla · Posted: Tue Jun 08, 2004 9:04 am Post subject:

fca, you are right!
just installed the current mm-sources (2.6.7-rc2-mm2) and my athlon is as fast as it should be!

i guess, it has something to do with the acpi/apic bug for nforce2 in the 2.6 kernels, which was mentioned in other threads.

hint for people with the same problem: 2.6.6-vanilla isn't enough!

thanks