Panic asus a7m266 with 2 512Mb PC2400 DDR333 memory

[Mario Sergio Fujikawa Ferreira]

Hi,

	Last thursday, I installed (20/Mar/2003) 2 kingston valueram
512Mb PC2400 DDR333 (KVR333X64C25/512) sticks on my A7M266 running
up to date -STABLE. The system became unstable right after installation,
any form of system load triggered a kernel panic: "Page Fault While
In Kernel Mode". My main test was the usual 'make buildworld'.

	I became worried about the quality of the memory
sticks. Therefore, I ran several forms of tests/benchmarks. memtest86
(http://www.memtest86.com/) worked right after running all tests
for 16 hours. prime95 (http://www.mersenne.org/) crunch test which
used about 900Mb of memory worked fine under Windows after 8 hours
or so. Then, I ran Sisandra 2003 burn-in test for about 4 hours.
Finally, I ran DocMemory 2.0 for 6 hours. All of them worked without
any glitches. No problems were found with the system.

	This small test battery got me wondering if this was not
somewhat related to some interaction between FreeBSD and the memory
sticks. I did several tests for days,

	1) tried very conservative bios settings (CAS 3T, etc)
	2) tried only 1 memory stick at a time on memory bay 1
	3) tried only 1 memory stick at a time on memory bay 2
	4) tried combination of all memory bios settings (took 5
	   days)
	5) tried increasing voltage supply of both chipset, memory
	   and processor, several combinations

	Windows is always fine with any of these settings. However,
FreeBSD was not happy with any. Then, I wondered if changing any
kernel build settings would make any difference. I changed a single
line

from

maxusers	0
	
to

maxusers	256

this made the system a lot more stable. I was able to use the machine
for several hours. It even survived 2 'make buildworld' but it panics
at the end nevertheless.

	One thing of interest, whenever the system panics, the IDE
hardware light would stay on till I hard reset the machine.

	Information about my system can be found at

- Kernel configuration file
http://people.FreeBSD.org/~lioux/boot/kernel

- sysctl settings
http://people.FreeBSD.org/~lioux/boot/sysctl.conf

- boot dmesg
http://people.FreeBSD.org/~lioux/boot/dmesg.boot

	Please let me know if any additional information could be
of help. On a side note, I placed this memory on another machine
(k7s5a motherboard + FreeBSD 4.6R), the system was rock solid. :(

	Regards,

ps: Please, CC: me when you reply. I only receive digests from
this mailing list.

-- 
Mario S F Ferreira - DF - Brazil - "I guess this is a signature."
FreeBSD Committer | CS Developer
flames to beloved devnull at someotherworldbeloworabove.org
feature, n: a documented bug | bug, n: an undocumented feature