Problems with AMD64 and 8 GB RAM?

[Greg 'groggy' Lehey]

I've recently acquired an AMD64 box (dual Opteron 242, SiS Master at -FAR
motherboard
(http://www.msi.com.tw/program/products/server/svr/pro_svr_detail.php?UID=484).
See below for more details).  I find it very unstable running with 8
GB memory, though 4 GB are not a problem.  At first I thought it was
the onboard peripherals, but after disabling them it still persisted.

What's unstable?  I only once got it through the boot process.
Running a 5.3-RELEASE i386 kernel it panics, though I haven't
investigated the panic (yet), since I'm not interested in the i386
kernel.  The amd64 5.4-PRERELEASE kernel just hangs/freezes.  When the
peripherals are enabled, it's after probing the onboard NIC (bge) and
before probing SATA (no drives present).  I've done a verbose boot, of
course, but no additional information is present.  The NIC is
recognized, and that's all.

Without the peripherals, but with a 3Com 3c905 PCI NIC, it continues
beyond this point, but doesn't enable the NIC.  I don't have dmesg
output for these attempts, so I can't produce the exact message, and I
suspect it's not important.  It continues until trying to mount NFS
file systems, where it hangs for obvious reasons.  Pressing ^C causes
the system to either panic (and be unable to dump because I don't have
that much swap) or just hang.

None of these problems occur when I use 4 GB memory.  About the only
strangeness, which seems to come from the BIOS, is that it recognizes
only 3.5 GB.  If I put all DIMMS in, it recognizes the full 8 GB
memory.

I realize that this isn't enough to diagnose the problem.  The reason
for this message now is to ask:

1.  Has anybody else seen this problem?
2.  Has anybody else used this hardware configuration and *not* seen
    this problem?
3.  Where should I look next?

I'm attaching the (non-verbose) dmesg from a successful boot.

Greg
--
See complete headers for address and phone numbers.

Mar 30 14:17:16 obelix kernel: FreeBSD 5.4-PRERELEASE #0: Tue Mar 22 04:02:17 UTC 2005
Mar 30 14:17:16 obelix kernel: root at obelix:/usr/obj/src/FreeBSD/OBELIX/src/sys/OBELIX
Mar 30 14:17:16 obelix kernel: Timecounter "i8254" frequency 1193182 Hz quality 0
Mar 30 14:17:16 obelix kernel: CPU: AMD Opteron(tm) Processor 242 (1603.65-MHz K8-class CPU)
Mar 30 14:17:16 obelix kernel: Origin = "AuthenticAMD"  Id = 0xf5a  Stepping = 10
Mar 30 14:17:16 obelix kernel: Features=0x78bfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE3
6,CLFLUSH,MMX,FXSR,SSE,SSE2>
Mar 30 14:17:16 obelix kernel: AMD Features=0xe0500800<SYSCALL,NX,MMX+,LM,3DNow+,3DNow>
Mar 30 14:17:16 obelix kernel: real memory  = 3756916736 (3582 MB)
Mar 30 14:17:16 obelix kernel: avail memory = 3623907328 (3456 MB)
Mar 30 14:17:16 obelix kernel: ACPI APIC Table: <VIAK8  AWRDACPI>
Mar 30 14:17:16 obelix kernel: FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
Mar 30 14:17:16 obelix kernel: cpu0 (BSP): APIC ID:  0
Mar 30 14:17:16 obelix kernel: cpu1 (AP): APIC ID:  1
Mar 30 14:17:16 obelix kernel: ioapic0: Changing APIC ID to 2
Mar 30 14:17:16 obelix kernel: ioapic0 <Version 0.3> irqs 0-23 on motherboard
Mar 30 14:17:16 obelix kernel: acpi0: <VIAK8 AWRDACPI> on motherboard
Mar 30 14:17:16 obelix kernel: acpi0: Power Button (fixed)
Mar 30 14:17:16 obelix kernel: Timecounter "ACPI-fast" frequency 3579545 Hz quality 1000
Mar 30 14:17:16 obelix kernel: acpi_timer0: <24-bit timer at 3.579545MHz> port 0x4008-0x400b on acpi0
Mar 30 14:17:16 obelix kernel: cpu0: <ACPI CPU> on acpi0
Mar 30 14:17:16 obelix kernel: cpu1: <ACPI CPU> on acpi0
Mar 30 14:17:16 obelix kernel: acpi_button0: <Power Button> on acpi0
Mar 30 14:17:16 obelix kernel: pcib0: <ACPI Host-PCI bridge> port 0xcf8-0xcff on acpi0
Mar 30 14:17:16 obelix kernel: pci0: <ACPI PCI bus> on pcib0
Mar 30 14:17:16 obelix kernel: pcib1: <PCI-PCI bridge> at device 1.0 on pci0
Mar 30 14:17:16 obelix kernel: pci1: <PCI bus> on pcib1
Mar 30 14:17:16 obelix kernel: pci1: <display, VGA> at device 0.0 (no driver attached)
Mar 30 14:17:16 obelix kernel: xl0: <3Com 3c905C-TX Fast Etherlink XL> port 0xd000-0xd07f mem 0xfb000000-0xfb00007f irq 
18 at device 7.0 on pci0
Mar 30 14:17:16 obelix kernel: miibus0: <MII bus> on xl0
Mar 30 14:17:16 obelix kernel: xlphy0: <3c905C 10/100 internal PHY> on miibus0
Mar 30 14:17:16 obelix kernel: xlphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
Mar 30 14:17:16 obelix kernel: xl0: Ethernet address: 00:50:da:cf:17:d3
Mar 30 14:17:16 obelix kernel: atapci0: <VIA 8237 UDMA133 controller> port 0xd400-0xd40f,0x376,0x170-0x177,0x3f6,0x1f0-0
x1f7 at device 15.0 on pci0
Mar 30 14:17:16 obelix kernel: ata0: channel #0 on atapci0
Mar 30 14:17:16 obelix kernel: ata1: channel #1 on atapci0
Mar 30 14:17:16 obelix kernel: uhci0: <VIA 83C572 USB controller> port 0xd800-0xd81f irq 21 at device 16.0 on pci0
Mar 30 14:17:16 obelix kernel: usb0: <VIA 83C572 USB controller> on uhci0
Mar 30 14:17:16 obelix kernel: usb0: USB revision 1.0
Mar 30 14:17:16 obelix kernel: uhub0: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
Mar 30 14:17:16 obelix kernel: uhub0: 2 ports with 2 removable, self powered
Mar 30 14:17:16 obelix kernel: uhci1: <VIA 83C572 USB controller> port 0xdc00-0xdc1f irq 21 at device 16.1 on pci0
Mar 30 14:17:16 obelix kernel: usb1: <VIA 83C572 USB controller> on uhci1
Mar 30 14:17:16 obelix kernel: usb1: USB revision 1.0
Mar 30 14:17:16 obelix kernel: uhub1: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
Mar 30 14:17:16 obelix kernel: uhub1: 2 ports with 2 removable, self powered
Mar 30 14:17:16 obelix kernel: uhci2: <VIA 83C572 USB controller> port 0xe000-0xe01f irq 21 at device 16.2 on pci0
Mar 30 14:17:16 obelix kernel: usb2: <VIA 83C572 USB controller> on uhci2
Mar 30 14:17:16 obelix kernel: usb2: USB revision 1.0
Mar 30 14:17:16 obelix kernel: uhub2: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
Mar 30 14:17:16 obelix kernel: uhub2: 2 ports with 2 removable, self powered
Mar 30 14:17:16 obelix kernel: pci0: <serial bus, USB> at device 16.4 (no driver attached)
Mar 30 14:17:16 obelix kernel: isab0: <PCI-ISA bridge> at device 17.0 on pci0
Mar 30 14:17:16 obelix kernel: isa0: <ISA bus> on isab0
Mar 30 14:17:16 obelix kernel: pci0: <multimedia, audio> at device 17.5 (no driver attached)
Mar 30 14:17:16 obelix kernel: acpi_tz0: <Thermal Zone> on acpi0
Mar 30 14:17:16 obelix kernel: fdc0: <floppy drive controller> port 0x3f7,0x3f0-0x3f5 irq 6 drq 2 on acpi0
Mar 30 14:17:16 obelix kernel: sio0: <16550A-compatible COM port> port 0x3f8-0x3ff irq 4 flags 0x10 on acpi0
Mar 30 14:17:16 obelix kernel: sio0: type 16550A
Mar 30 14:17:16 obelix kernel: sio1: <16550A-compatible COM port> port 0x2f8-0x2ff irq 3 on acpi0
Mar 30 14:17:16 obelix kernel: sio1: type 16550A
Mar 30 14:17:16 obelix kernel: ppc0: <Standard parallel printer port> port 0x778-0x77b,0x378-0x37f irq 7 on acpi0
Mar 30 14:17:16 obelix kernel: ppc0: Generic chipset (NIBBLE-only) in COMPATIBLE mode
Mar 30 14:17:16 obelix kernel: ppbus0: <Parallel port bus> on ppc0
Mar 30 14:17:16 obelix kernel: plip0: <PLIP network interface> on ppbus0
Mar 30 14:17:16 obelix kernel: lpt0: <Printer> on ppbus0
Mar 30 14:17:16 obelix kernel: lpt0: Interrupt-driven port
Mar 30 14:17:16 obelix kernel: ppi0: <Parallel I/O> on ppbus0
Mar 30 14:17:16 obelix kernel: atkbdc0: <Keyboard controller (i8042)> port 0x64,0x60 irq 1 on acpi0
Mar 30 14:17:16 obelix kernel: atkbd0: <AT Keyboard> flags 0x1 irq 1 on atkbdc0
Mar 30 14:17:16 obelix kernel: kbd0 at atkbd0
Mar 30 14:17:16 obelix kernel: orm0: <ISA Option ROMs> at iomem 0xd0000-0xd07ff,0xc0000-0xcffff on isa0
Mar 30 14:17:16 obelix kernel: sc0: <System console> at flags 0x100 on isa0
Mar 30 14:17:16 obelix kernel: sc0: VGA <16 virtual consoles, flags=0x300>
Mar 30 14:17:16 obelix kernel: vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0
Mar 30 14:17:16 obelix kernel: Timecounters tick every 1.000 msec
Mar 30 14:17:16 obelix kernel: ad0: 190782MB <ST3200826A/3.01> [387621/16/63] at ata0-master UDMA100
Mar 30 14:17:16 obelix kernel: ad1: 190782MB <ST3200826A/3.01> [387621/16/63] at ata0-slave UDMA100
Mar 30 14:17:16 obelix kernel: acd0: DVDR <PIONEER DVD-RW DVR-108/1.04> at ata1-master UDMA66
Mar 30 14:17:16 obelix kernel: SMP: AP CPU #1 Launched!
Mar 30 14:17:16 obelix kernel: Mounting root from ufs:/dev/ad0s1a
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 187 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-amd64/attachments/20050331/b671270f/attachment.bin