Problem with Asus P4C800-DX and P4 -Northwood-

From: Andreas Baer
Date: Sun Jul 24 2005 - 19:49:14 EST

Hi everyone,

First I want to say sorry for this BIG post, but it seems that I have no other chance. :)

I have a Asus P4C800-DX with a P4 2,4 GHz 512 KB L2 Cache "Northwood" Processor (lowest Processor that supports HyperThreading) and 1GB DDR400 RAM. I'm also running S-ATA disks with about 50 MB/s (just to show that it shouldn't be due to hard disk speed). Everything was bought back in 2003 and I recently upgraded to the lastest BIOS Version. I've installed Gentoo Linux and WinXP with dual-boot on this system.

Now to my problem:

I'm currently developing a little database in C++ (runs currently under Windows and Linux) that internally builds up an R-Tree and does a lot of equality tests and other time consuming checks. For perfomance issue I ran a test with 200000 entries and it took me about 3 minutes to complete under Gentoo Linux.

So I ran the same test in Windows on the same platform and it took about 30(!) seconds. I was a little bit surprised about this result so I started to run several tests on different machines like an Athlon XP 2000+ platform and on my P4 3GHz "Prescott" Notebook and they all showed something about 30 seconds or below. Then I began to search for errors or any misconfiguration in Gentoo, in my code and also for people that have made equal experiences with that hardware configuration on the internet. I thought I have a problem with a broken gcc or libraries like glibc or libstdc++ and so I recompiled my whole system with the stable gcc 3.3.5 release, but that didn't make any changes. I also tried an Ubuntu and a Suse LiveCD to verify that it has nothing to do with Gentoo and my kernel version and they had the same problem and ran the test in about 3 min.

Currently I'm at a loss what to do. I'm beginning to think that this is maybe a kernel problem because I have no problems under Windows and it doesn't matter whether I change any software or any configuration in Gentoo. I'm currently running kernel-2.6.12, but the Livecd's had other kernels.

HyperThreading(HT) is also not the reason for the loss of power, because I tried to disable it and to create a uniprocessor kernel, but that didn't solve the problem.

If you need some output of my configuration/log files or anything like that, just mail me.

Is it possible that the kernel has a lack of support for P4 with "Northwood" core? Maybe only this one? Could I solve the problem if I change the processor to a "Prescott" core? Perhaps someone could provide any information if this would make any sense or not.

Thanks in advance for anything that could help.

...sorry for bad english :)
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