I have an AMD64 machine, a single stick of 512 MB RAM, with Kubuntu 6.06 x86 installed. It will spontaneously log out, or with either Konqueror or Firefox running, crash one or the other application.

I looked into the syslog after it crashed a Konqueror page - I had an instance of Konqueror on two desktops - and on or around the line that mentioned Signal 15, it hinted about "corrupt RAM".

I looked into dmesg and it reports something like 460MB RAM as lowmem, and none as highmem. I have a second machine running Kubuntu 6.06, and it reports 1GB RAM as roughly 800MB lowmem and 200MB as highmem; the total is roughly what it should be.

Is this an indication of bad RAM?

thx

It is possibly, but before throwing it out or replacing it, pull it out and reseat it. Could be a bit of dust or just not 100% positive contact. Failing that, look for a memtest command and try and test the stick that way.

Hi! I have 512MB of total ram (1 stick) and I report no High mem either.

I'm a newb to this kind of stuff. Below is my 'dmesg'. Can I optimize anything?

[B]bigboss@bigboss-desktop:~$ dmesg
[17179569.184000] Linux version 2.6.15-26-386 (buildd@terranova) (gcc version 4.0.3 (Ubuntu 4.0.3-1ubuntu5)) #1 PREEMPT Thu Aug 3 02:52:00 UTC 2006
[17179569.184000] BIOS-provided physical RAM map:
[17179569.184000] BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
[17179569.184000] BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
[17179569.184000] BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
[17179569.184000] BIOS-e820: 0000000000100000 - 000000001fef0000 (usable)
[17179569.184000] BIOS-e820: 000000001fef0000 - 000000001fef3000 (ACPI NVS)
[17179569.184000] BIOS-e820: 000000001fef3000 - 000000001ff00000 (ACPI data)
[17179569.184000] BIOS-e820: 00000000fec00000 - 0000000100000000 (reserved)
[17179569.184000] 0MB HIGHMEM available.
[17179569.184000] 510MB LOWMEM available.
[17179569.184000] found SMP MP-table at 000f4f00
[17179569.184000] On node 0 totalpages: 130800
[17179569.184000] DMA zone: 4096 pages, LIFO batch:0
[17179569.184000] DMA32 zone: 0 pages, LIFO batch:0
[17179569.184000] Normal zone: 126704 pages, LIFO batch:31
[17179569.184000] HighMem zone: 0 pages, LIFO batch:0
[17179569.184000] DMI 2.3 present.
[17179569.184000] ACPI: RSDP (v000 P4M800 ) @ 0x000f6f40
[17179569.184000] ACPI: RSDT (v001 P4M800 AWRDACPI 0x42302e31 AWRD 0x00000000) @ 0x1fef3040
[17179569.184000] ACPI: FADT (v001 P4M800 AWRDACPI 0x42302e31 AWRD 0x00000000) @ 0x1fef30c0
[17179569.184000] ACPI: MADT (v001 P4M800 AWRDACPI 0x42302e31 AWRD 0x00000000) @ 0x1fef8540
[17179569.184000] ACPI: DSDT (v001 P4M800 AWRDACPI 0x00001000 MSFT 0x0100000e) @ 0x00000000
[17179569.184000] ACPI: PM-Timer IO Port: 0x408
[17179569.184000] ACPI: Local APIC address 0xfee00000
[17179569.184000] ACPI: LAPIC (acpi_id[0x00] lapic_id[0x00] enabled)
[17179569.184000] Processor #0 15:4 APIC version 20
[17179569.184000] ACPI: LAPIC (acpi_id[0x01] lapic_id[0x01] disabled)
[17179569.184000] ACPI: LAPIC_NMI (acpi_id[0x00] high edge lint[0x1])
[17179569.184000] ACPI: LAPIC_NMI (acpi_id[0x01] high edge lint[0x1])
[17179569.184000] ACPI: IOAPIC (id[0x02] address[0xfec00000] gsi_base[0])
[17179569.184000] IOAPIC[0]: apic_id 2, version 3, address 0xfec00000, GSI 0-23
[17179569.184000] ACPI: INT_SRC_OVR (bus 0 bus_irq 0 global_irq 2 dfl dfl)
[17179569.184000] ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 low level)
[17179569.184000] ACPI: IRQ0 used by override.
[17179569.184000] ACPI: IRQ2 used by override.
[17179569.184000] ACPI: IRQ9 used by override.
[17179569.184000] Enabling APIC mode: Flat. Using 1 I/O APICs
[17179569.184000] Using ACPI (MADT) for SMP configuration information
[17179569.184000] Allocating PCI resources starting at 20000000 (gap: 1ff00000:ded00000)
[17179569.184000] Built 1 zonelists
[17179569.184000] Kernel command line: root=/dev/hda1 ro quiet splash
[17179569.184000] mapped APIC to ffffd000 (fee00000)
[17179569.184000] mapped IOAPIC to ffffc000 (fec00000)
[17179569.184000] Initializing CPU#0
[17179569.184000] PID hash table entries: 2048 (order: 11, 32768 bytes)
[17179569.184000] Detected 2667.492 MHz processor.
[17179569.184000] Using pmtmr for high-res timesource
[17179569.184000] Console: colour VGA+ 80x25
[17179571.980000] Dentry cache hash table entries: 65536 (order: 6, 262144 bytes)
[17179571.980000] Inode-cache hash table entries: 32768 (order: 5, 131072 bytes)[17179571.988000] Memory: 508212k/523200k available (1976k kernel code, 14412k reserved, 606k data, 288k init, 0k highmem)
[17179571.988000] Checking if this processor honours the WP bit even in supervisor mode... Ok.
[17179572.068000] Calibrating delay using timer specific routine.. 5340.66 BogoMIPS (lpj=10681336)
[17179572.068000] Security Framework v1.0.0 initialized
[17179572.068000] SELinux: Disabled at boot.
[17179572.068000] Mount-cache hash table entries: 512
[17179572.068000] CPU: After generic identify, caps: bfebfbff 20000000 00000000 00000000 0000651d 00000000 00000000
[17179572.068000] CPU: After vendor identify, caps: bfebfbff 20000000 00000000 00000000 0000651d 00000000 00000000
[17179572.068000] monitor/mwait feature present.
[17179572.068000] using mwait in idle threads.
[17179572.068000] CPU: Trace cache: 12K uops, L1 D cache: 16K
[17179572.068000] CPU: L2 cache: 1024K
[17179572.068000] CPU: After all inits, caps: bfebfbff 20000000 00000000 00000080 0000651d 00000000 00000000
[17179572.068000] mtrr: v2.0 (20020519)
[17179572.068000] CPU: Intel(R) Pentium(R) 4 CPU 2.66GHz stepping 01
[17179572.068000] Enabling fast FPU save and restore... done.
[17179572.068000] Enabling unmasked SIMD FPU exception support... done.
[17179572.068000] Checking 'hlt' instruction... OK.
[17179572.084000] checking if image is initramfs... it is
[17179572.660000] Freeing initrd memory: 6617k freed
[17179572.672000] ACPI: Looking for DSDT ... not found!
[17179572.684000] ENABLING IO-APIC IRQs
[17179572.684000] ..TIMER: vector=0x31 apic1=0 pin1=2 apic2=-1 pin2=-1
[17179572.828000] NET: Registered protocol family 16
[17179572.828000] EISA bus registered
[17179572.828000] ACPI: bus type pci registered
[17179572.828000] PCI: PCI BIOS revision 2.10 entry at 0xfb3b0, last bus=1
[17179572.828000] PCI: Using configuration type 1
[17179572.832000] ACPI: Subsystem revision 20051216
[17179572.844000] ACPI: Interpreter enabled
[17179572.844000] ACPI: Using IOAPIC for interrupt routing
[17179572.844000] ACPI: PCI Root Bridge [PCI0] (0000:00)
[17179572.844000] PCI: Probing PCI hardware (bus 00)
[17179572.848000] Boot video device is 0000:01:00.0
[17179572.848000] ACPI: PCI Interrupt Routing Table [\_SB_.PCI0._PRT]
[17179572.916000] ACPI: PCI Interrupt Link [LNKA] (IRQs 3 4 6 7 *10 11 12)
[17179572.916000] ACPI: PCI Interrupt Link [LNKB] (IRQs 3 4 6 7 10 *11 12)
[17179572.916000] ACPI: PCI Interrupt Link [LNKC] (IRQs 3 4 6 7 10 *11 12)
[17179572.920000] ACPI: PCI Interrupt Link [LNKD] (IRQs 3 4 6 7 10 11 12) *5
[17179572.920000] ACPI: PCI Interrupt Link [LNKE] (IRQs 3 4 6 7 10 11 12) *0, disabled.
[17179572.920000] ACPI: PCI Interrupt Link [LNKF] (IRQs 3 4 6 7 10 11 12) *0, disabled.
[17179572.920000] ACPI: PCI Interrupt Link [LNK0] (IRQs 3 4 6 7 10 11 12) *0, disabled.
[17179572.920000] ACPI: PCI Interrupt Link [LNK1] (IRQs 3 4 6 7 10 11 12) *0, disabled.
[17179572.920000] ACPI: PCI Interrupt Link [ALKA] (IRQs *20)
[17179572.920000] ACPI: PCI Interrupt Link [ALKB] (IRQs *21)
[17179572.920000] ACPI: PCI Interrupt Link [ALKC] (IRQs *22)
[17179572.924000] ACPI: PCI Interrupt Link [ALKD] (IRQs *23)
[17179572.924000] Linux Plug and Play Support v0.97 (c) Adam Belay
[17179572.924000] pnp: PnP ACPI init
[17179572.932000] pnp: PnP ACPI: found 13 devices
[17179572.932000] PnPBIOS: Disabled by ACPI PNP
[17179572.932000] PCI: Using ACPI for IRQ routing
[17179572.932000] PCI: If a device doesn't work, try "pci=routeirq". If it helps, post a report
[17179572.944000] pnp: 00:01: ioport range 0x400-0x47f could not be reserved
[17179572.944000] pnp: 00:01: ioport range 0x500-0x50f has been reserved
[17179572.944000] PCI: Bridge: 0000:00:01.0
[17179572.944000] IO window: d000-dfff
[17179572.944000] MEM window: f9000000-f90fffff
[17179572.944000] PREFETCH window: e8000000-f7ffffff
[17179572.944000] PCI: Setting latency timer of device 0000:00:01.0 to 64
[17179572.944000] audit: initializing netlink socket (disabled)
[17179572.944000] audit(1156279336.944:1): initialized
[17179572.944000] VFS: Disk quotas dquot_6.5.1
[17179572.944000] Dquot-cache hash table entries: 1024 (order 0, 4096 bytes)
[17179572.944000] Initializing Cryptographic API
[17179572.944000] io scheduler noop registered
[17179572.944000] io scheduler anticipatory registered
[17179572.944000] io scheduler deadline registered
[17179572.944000] io scheduler cfq registered
[17179572.944000] PCI: Bypassing VIA 8237 APIC De-Assert Message
[17179572.944000] isapnp: Scanning for PnP cards...
[17179573.296000] isapnp: No Plug & Play device found
[17179573.316000] PNP: PS/2 Controller [PNP0303:PS2K,PNP0f13:PS2M] at 0x60,0x64 irq 1,12
[17179573.316000] serio: i8042 AUX port at 0x60,0x64 irq 12
[17179573.316000] serio: i8042 KBD port at 0x60,0x64 irq 1
[17179573.316000] Serial: 8250/16550 driver $Revision: 1.90 $ 48 ports, IRQ sharing enabled
[17179573.316000] serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
[17179573.316000] serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
[17179573.320000] 00:08: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
[17179573.320000] 00:09: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
[17179573.320000] RAMDISK driver initialized: 16 RAM disks of 65536K size 1024 blocksize
[17179573.320000] Uniform Multi-Platform E-IDE driver Revision: 7.00alpha2
[17179573.320000] ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
[17179573.320000] mice: PS/2 mouse device common for all mice
[17179573.320000] EISA: Probing bus 0 at eisa.0
[17179573.320000] EISA: Detected 0 cards.
[17179573.320000] NET: Registered protocol family 2
[17179573.344000] input: AT Translated Set 2 keyboard as /class/input/input0
[17179573.356000] IP route cache hash table entries: 4096 (order: 2, 16384 bytes)
[17179573.356000] TCP established hash table entries: 16384 (order: 4, 65536 bytes)
[17179573.356000] TCP bind hash table entries: 16384 (order: 4, 65536 bytes)
[17179573.356000] TCP: Hash tables configured (established 16384 bind 16384)
[17179573.356000] TCP reno registered
[17179573.356000] TCP bic registered
[17179573.356000] NET: Registered protocol family 1
[17179573.356000] NET: Registered protocol family 8
[17179573.356000] NET: Registered protocol family 20
[17179573.356000] Using IPI Shortcut mode
[17179573.356000] ACPI wakeup devices:
[17179573.356000] SLPB PCI0 USB3 USB4 USB5 USB6 USB7 LAN0 AC97 MC97 UAR1
[17179573.356000] ACPI: (supports S0 S1 S4 S5)
[17179573.356000] Freeing unused kernel memory: 288k freed
[17179573.400000] vga16fb: initializing
[17179573.400000] vga16fb: mapped to 0xc00a0000
[17179573.500000] Console: switching to colour frame buffer device 80x25
[17179573.500000] fb0: VGA16 VGA frame buffer device
[17179574.624000] Capability LSM initialized
[17179574.652000] ACPI: Fan [FAN] (on)
[17179574.656000] ACPI: Thermal Zone [THRM] (60 C)
[17179575.136000] SCSI subsystem initialized
[17179575.140000] ACPI: bus type scsi registered
[17179575.140000] libata version 1.20 loaded.
[17179575.140000] sata_via 0000:00:0f.0: version 1.1
[17179575.140000] **** SET: Misaligned resource pointer: de96cc02 Type 07 Len 0
[17179575.140000] ACPI: PCI Interrupt Link [ALKA] enabled at IRQ 20
[17179575.140000] ACPI: PCI Interrupt 0000:00:0f.0[B] -> Link [ALKA] -> GSI 20 (level, low) -> IRQ 169
[17179575.140000] sata_via 0000:00:0f.0: routed to hard irq line 11
[17179575.140000] ata1: SATA max UDMA/133 cmd 0xE000 ctl 0xE102 bmdma 0xE400 irq 169
[17179575.140000] ata2: SATA max UDMA/133 cmd 0xE200 ctl 0xE302 bmdma 0xE408 irq 169
[17179576.312000] scsi0 : sata_via
[17179577.484000] scsi1 : sata_via
[17179577.500000] VP_IDE: IDE controller at PCI slot 0000:00:0f.1
[17179577.500000] ACPI: PCI Interrupt 0000:00:0f.1[A] -> Link [ALKA] -> GSI 20 (level, low) -> IRQ 169
[17179577.500000] PCI: VIA IRQ fixup for 0000:00:0f.1, from 255 to 9
[17179577.500000] VP_IDE: chipset revision 6
[17179577.500000] VP_IDE: not 100% native mode: will probe irqs later
[17179577.500000] VP_IDE: VIA vt8237 (rev 00) IDE UDMA133 controller on pci0000:00:0f.1
[17179577.500000] ide0: BM-DMA at 0xe600-0xe607, BIOS settings: hdaMA, hdbMA
[17179577.500000] ide1: BM-DMA at 0xe608-0xe60f, BIOS settings: hdcMA, hddMA
[17179577.500000] Probing IDE interface ide0...
[17179577.916000] hda: Maxtor 6L120P0, ATA DISK drive
[17179578.196000] hdb: QUANTUM FIREBALLlct20 20, ATA DISK drive
[17179578.252000] ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
[17179578.280000] Probing IDE interface ide1...
[17179579.148000] hdc: SONY CD-RW CRX320EE, ATAPI CD/DVD-ROM drive
[17179579.932000] hdd: CD-ROM 24X/AKOx, ATAPI CD/DVD-ROM drive
[17179579.988000] ide1 at 0x170-0x177,0x376 on irq 15
[17179580.004000] hda: max request size: 128KiB
[17179580.016000] hda: 240121728 sectors (122942 MB) w/8192KiB Cache, CHS=65535/16/63, UDMA(133)
[17179580.020000] hda: cache flushes supported
[17179580.020000] hda: hda1 hda2 < hda5 >
[17179580.056000] hdb: max request size: 128KiB
[17179580.060000] hdb: 39876480 sectors (20416 MB) w/418KiB Cache, CHS=39560/16/63
[17179580.060000] hdb: cache flushes not supported
[17179580.060000] hdb:<6>hdc: ATAPI 52X DVD-ROM CD-R/RW drive, 1536kB Cache, UDMA(33)
[17179580.060000] Uniform CD-ROM driver Revision: 3.20
[17179580.064000] hdd: ATAPI 24X CD-ROM drive, 120kB Cache, DMA
[17179580.064000] hdb1
[17179580.520000] usbcore: registered new driver usbfs
[17179580.520000] usbcore: registered new driver hub
[17179580.520000] USB Universal Host Controller Interface driver v2.3
[17179580.520000] **** SET: Misaligned resource pointer: dfbbf7c2 Type 07 Len 0
[17179580.524000] ACPI: PCI Interrupt Link [ALKB] enabled at IRQ 21
[17179580.524000] ACPI: PCI Interrupt 0000:00:10.0[A] -> Link [ALKB] -> GSI 21 (level, low) -> IRQ 177
[17179580.524000] PCI: VIA IRQ fixup for 0000:00:10.0, from 10 to 1
[17179580.524000] uhci_hcd 0000:00:10.0: UHCI Host Controller
[17179580.524000] uhci_hcd 0000:00:10.0: new USB bus registered, assigned bus number 1
[17179580.524000] uhci_hcd 0000:00:10.0: irq 177, io base 0x0000e700
[17179580.524000] hub 1-0:1.0: USB hub found
[17179580.524000] hub 1-0:1.0: 2 ports detected
[17179580.628000] ACPI: PCI Interrupt 0000:00:10.1[A] -> Link [ALKB] -> GSI 21 (level, low) -> IRQ 177
[17179580.628000] PCI: VIA IRQ fixup for 0000:00:10.1, from 10 to 1
[17179580.628000] uhci_hcd 0000:00:10.1: UHCI Host Controller
[17179580.628000] uhci_hcd 0000:00:10.1: new USB bus registered, assigned bus number 2
[17179580.628000] uhci_hcd 0000:00:10.1: irq 177, io base 0x0000e800
[17179580.628000] hub 2-0:1.0: USB hub found
[17179580.628000] hub 2-0:1.0: 2 ports detected
[17179580.732000] ACPI: PCI Interrupt 0000:00:10.2[B] -> Link [ALKB] -> GSI 21 (level, low) -> IRQ 177
[17179580.732000] PCI: VIA IRQ fixup for 0000:00:10.2, from 11 to 1
[17179580.732000] uhci_hcd 0000:00:10.2: UHCI Host Controller
[17179580.732000] uhci_hcd 0000:00:10.2: new USB bus registered, assigned bus number 3
[17179580.732000] uhci_hcd 0000:00:10.2: irq 177, io base 0x0000e900
[17179580.732000] hub 3-0:1.0: USB hub found
[17179580.732000] hub 3-0:1.0: 2 ports detected
[17179580.836000] ACPI: PCI Interrupt 0000:00:10.3 -> Link [ALKB] -> GSI 21 (level, low) -> IRQ 177
[17179580.836000] PCI: VIA IRQ fixup for 0000:00:10.3, from 11 to 1
[17179580.836000] uhci_hcd 0000:00:10.3: UHCI Host Controller
[17179580.836000] uhci_hcd 0000:00:10.3: new USB bus registered, assigned bus number 4
[17179580.836000] uhci_hcd 0000:00:10.3: irq 177, io base 0x0000ea00
[17179580.836000] hub 4-0:1.0: USB hub found
[17179580.836000] hub 4-0:1.0: 2 ports detected
[17179580.940000] ACPI: PCI Interrupt 0000:00:10.4[C] -> Link [ALKB] -> GSI 21 (level, low) -> IRQ 177
[17179580.940000] ehci_hcd 0000:00:10.4: EHCI Host Controller
[17179580.940000] ehci_hcd 0000:00:10.4: new USB bus registered, assigned bus number 5
[17179580.940000] ehci_hcd 0000:00:10.4: irq 177, io mem 0xf9100000
[17179580.940000] ehci_hcd 0000:00:10.4: USB 2.0 started, EHCI 1.00, driver 10 Dec 2004
[17179580.940000] hub 5-0:1.0: USB hub found
[17179580.940000] hub 5-0:1.0: 8 ports detected
[17179581.144000] Attempting manual resume
[17179581.156000] kjournald starting. Commit interval 5 seconds
[17179581.156000] EXT3-fs: mounted filesystem with ordered data mode.
[17179582.232000] usb 2-2: new full speed USB device using uhci_hcd and address 2
[17179589.792000] Linux agpgart interface v0.101 (c) Dave Jones
[17179589.796000] agpgart: Detected VIA P4M800 chipset
[17179589.804000] agpgart: AGP aperture is 128M @ 0xe0000000
[17179589.980000] pci_hotplug: PCI Hot Plug PCI Core version: 0.5
[17179589.984000] shpchp: Standard Hot Plug PCI Controller Driver version: 0.4
[17179590.080000] Real Time Clock Driver v1.12
[17179590.112000] Floppy drive(s): fd0 is 1.44M
[17179590.112000] input: PC Speaker as /class/input/input1
[17179590.124000] via-rhine.c:v1.10-LK1.2.0-2.6 June-10-2004 Written by Donald Becker
[17179590.124000] **** SET: Misaligned resource pointer: da8c4f02 Type 07 Len 0
[17179590.124000] ACPI: PCI Interrupt Link [ALKD] enabled at IRQ 23
[17179590.124000] ACPI: PCI Interrupt 0000:00:12.0[A] -> Link [ALKD] -> GSI 23 (level, low) -> IRQ 185
[17179590.128000] eth0: VIA Rhine II at 0x1ed00, 00:13:d3:aa:17:b0, IRQ 185.
[17179590.128000] eth0: MII PHY found at address 1, status 0x7849 advertising 01e1 Link 0000.
[17179590.132000] FDC 0 is a post-1991 82077
[17179590.132000] Linux video capture interface: v1.00
[17179590.188000] cx2388x v4l2 driver version 0.0.5 loaded
[17179590.188000] ACPI: PCI Interrupt 0000:00:08.0[A] -> GSI 19 (level, low) -> IRQ 193
[17179590.188000] CORE cx88[0]: subsystem: 1002:00f8, board: ATI TV Wonder Pro [card=4,autodetected]
[17179590.188000] TV tuner 44 at 0x1fe, Radio tuner -1 at 0x1fe
[17179590.396000] cx88[0]/0: found at 0000:00:08.0, rev: 5, irq: 193, latency: 32, mmio: 0xf8000000
[17179590.604000] tuner 1-0060: All bytes are equal. It is not a TEA5767
[17179590.604000] tuner 1-0060: chip found @ 0xc0 (cx88[0])
[17179590.604000] tuner 1-0060: type set to 44 (Philips 4 in 1 (ATI TV Wonder Pro/Conexant))
[17179590.652000] tda9887 1-0043: chip found @ 0x86 (cx88[0])
[17179590.656000] cx88[0]/0: registered device video0 [v4l2]
[17179590.656000] cx88[0]/0: registered device vbi0
[17179590.668000] **** SET: Misaligned resource pointer: da8c4a02 Type 07 Len 0
[17179590.668000] ACPI: PCI Interrupt Link [ALKC] enabled at IRQ 22
[17179590.668000] ACPI: PCI Interrupt 0000:00:11.5[C] -> Link [ALKC] -> GSI 22 (level, low) -> IRQ 201
[17179590.668000] PCI: Setting latency timer of device 0000:00:11.5 to 64
[17179590.680000] parport: PnPBIOS parport detected.
[17179590.680000] parport0: PC-style at 0x378 (0x778), irq 7, dma 3 [PCSPP,TRISTATE,COMPAT,EPP,ECP,DMA]
[17179590.688000] drivers/usb/net/atmel/at76_usbdfu.c: USB Device Firmware Upgrade (DFU) handler v0.12beta23-fw_dwl loading
[17179590.692000] drivers/usb/net/atmel/at76c503.c: Generic Atmel at76c503/at76c505 routines v0.12beta23-fw_dwl
[17179590.692000] drivers/usb/net/atmel/at76c503-fw_skel.c: Atmel at76c503 (RFMD) Wireless LAN Driver v0.12beta23-fw_dwl loading
[17179590.692000] drivers/usb/net/atmel/at76c503-fw_skel.c: downloading firmware atmel_at76c503-rfmd.bin
[17179590.768000] parport0: Printer, HEWLETT-PACKARD DESKJET 3820
[17179590.832000] drivers/usb/net/atmel/at76c503-fw_skel.c: got it.
[17179590.836000] drivers/usb/net/atmel/at76c503.c: $Id: at76c503.c,v 1.74 2005/03/08 01:33:14 jal2 Exp $ compiled Aug 3 2006 03:05:22
[17179590.836000] drivers/usb/net/atmel/at76c503.c: firmware version 1.101.4 #84 (fcs_len 4)
[17179590.836000] drivers/usb/net/atmel/at76c503.c: device's MAC 00:06:25:27:49:85, regulatory domain FCC (U.S) (id 16)
[17179590.836000] drivers/usb/net/atmel/at76c503.c: registered wlan0
[17179590.836000] usbcore: registered new driver at76c503-rfmd
[17179590.952000] input: ImPS/2 Generic Wheel Mouse as /class/input/input2
[17179590.980000] ts: Compaq touchscreen protocol output
[17179591.660000] lp0: using parport0 (interrupt-driven).
[17179591.708000] Adding 1502036k swap on /dev/hda5. Priority:-1 extents:1 across:1502036k
[17179591.860000] EXT3 FS on hda1, internal journal
[17179592.016000] md: md driver 0.90.3 MAX_MD_DEVS=256, MD_SB_DISKS=27
[17179592.016000] md: bitmap version 4.39
[17179592.116000] NET: Registered protocol family 17
[17179592.620000] device-mapper: 4.4.0-ioctl (2005-01-12) initialised: dm-devel@redhat.com
[17179592.876000] cdrom: open failed.
[17179593.288000] cdrom: open failed.
[17179595.776000] cdrom: open failed.
[17179596.432000] kjournald starting. Commit interval 5 seconds
[17179596.432000] EXT3 FS on hdb1, internal journal
[17179596.432000] EXT3-fs: mounted filesystem with ordered data mode.
[17179600.480000] NET: Registered protocol family 10
[17179600.480000] lo: Disabled Privacy Extensions
[17179600.480000] IPv6 over IPv4 tunneling driver
[17179600.992000] ACPI: Power Button (FF) [PWRF]
[17179600.992000] ACPI: Power Button (CM) [PWRB]
[17179600.992000] ACPI: Sleep Button (CM) [SLPB]
[17179601.084000] ibm_acpi: ec object not found
[17179601.112000] pcc_acpi: loading...
[17179604.544000] [drm] Initialized drm 1.0.1 20051102
[17179604.548000] ACPI: PCI Interrupt 0000:01:00.0[A] -> GSI 16 (level, low) -> IRQ 209
[17179604.552000] [drm] Initialized radeon 1.24.0 20060225 on minor 0
[17179605.252000] ppdev: user-space parallel port driver
[17179605.612000] agpgart: Found an AGP 3.5 compliant device at 0000:00:00.0.
[17179605.612000] agpgart: Putting AGP V3 device at 0000:00:00.0 into 4x mode
[17179605.612000] agpgart: Putting AGP V3 device at 0000:01:00.0 into 4x mode
[17179605.744000] apm: BIOS version 1.2 Flags 0x07 (Driver version 1.16ac)
[17179605.744000] apm: overridden by ACPI.
[17179605.956000] [drm] Setting GART location based on new memory map
[17179605.956000] [drm] Loading R200 Microcode
[17179605.956000] [drm] writeback test succeeded in 1 usecs

I put the RAM in the other RAM slot in the computer and seated it well. I then downloaded a copy of memtest86+ from <www.memtest.org> , burned it to CD and booted the suspect computer with it.

It would only test 447MB of the 512MB stick, and that portion seemed to pass okay. I tried to adjust the test parameters so that it would look at the upper range [ 448MB - 512MB ], but it never would see the remaining untested RAM.

I think this is bad RAM. Any confirming opinions?

thx

Forget about highmem - only an issue as you approach 1 Gig (as per your second machine).
As for your "problem", I'd be thinking your BIOS is reseving RAM; video would be a good suspect. Nothing Linux (or you probably) can do about that.
Be happy that what you are using passes memtest o.k.

I can live with that! Now I better understand the HighMem concept!

Sorry that I am hijacking this thread, but hey..,it worked! lol!

If RAM is potentially ruled out as a suspect, I guess I am back to my original question: what could be making this machine intermittently unstable -- like spontaneously sending me back to the log in page?

Should I add another stick of 512K to boost the total to 1GB for 64 bit hardware?

thx

I may have found the source of the instability. I went to mobo manufacturer's [ MSI ] web site, and found a note in Troubleshooting that mentioned that MSI could not guarantee that the BIOS would auto-configure the RAM properly. They advised checking the RAM specs for voltage, etc, and check that against the BIOS. Sure enough, the voltage was wrong. I adjusted it in the BIOS and booted, and so far no crashes.

So I'd still like to know: why does Kubuntu only want to see 87% [ 447MB out 512MB ] of the RAM capacity of the machine?

thx

Because, as syg00 said, your BIOS may be reserving memory for things like an onboard video card. Do you have onboard video?

also, you could have just put the ramstick in the known good machine and vice versa to test it. good job of research at the manufacturers site too.