<SOLVED>:"Lost" 1.1 gigabytes of memory: where did it go?
Posted: Fri Aug 07, 2015 2:14 am
Hi,
I have a Toshiba Satellite A100-497 (PSAA9E-0P004QSP) with 2 GB of memory that was running Windows XP (horribly at that) and thought it would be a good thing to try Mint. I also thought that it might be fun to try replace the drive with a refurbished SSD. I installed from a DVD using the linuxmint-17.2-cinnamon-64bit.iso image. I only ran into one issue (it seemed to hang on boot with a black screen or a black screen with a cursor) but I solved it by booting into recovery mode and then installing the Nvidia binary driver. So after this everything seemed very pleasing (not that I have played with it very much yet but everything loads fast and everything seems responsive).
So I had this 4 GB of memory lying around and decide it would be great to double the memory (even if it's just to reduce the number of writes to the SSD). I do this and I am not showing the full 4 GB of memory. In fact, it is showing a number that is suspiciously close to the 3 GB limit, 2.9 GB.
BIOS (which is the latest version) shows the laptop to have 4 GB of memory installed and the specifications listed by Toshiba say it can handle a maximum of 4 GB of RAM.
I ran the Memtest86+ test just to see and the result seems peculiar. It recognizes that there are two memory slots with installed memory and it is correctly identified but it is only seeing 3 GB of it, as far as I can tell. See graphic (it's a picture of a laptop screen taken through a webcam so sorry about the low quality):
[rimg]https://farm4.staticflickr.com/3670/197 ... 4cb7_o.png[/rimg]
The graphical System Information application shows the following:
What I am seeing is that I downloaded a 64 bit image, the system is recognizing a 64 bit operating system and it is running on a 64 bit CPU.
Oh, and I did consider that some memory might be shared with the video (the BIOS offers no settings dealing with video) but:
Either of the two memory slots works with either of the two memory modules and all four combinations show up as 2 GB of system memory. Having both slots filled and with the order reversed results in 2.9 GB of system memory being shown. So 2 filled slots give 2.9 GB and 1 filled slot gives 2 GB (that is, when it comes to these memory modules, there appears to be no hint of a fault following a piece of hardware).
I did find one example of someone reporting what to me seemed like a similar issue but I'm a bit of a newbie and I can't necessarily make sense of this. Some of the diagnostics they suggested are as follows:
"free -m" yields:
"uname -r" yields:
"file `which free`" yields:
"dmidecode --type memory" yields:
"cat /proc/meminfo" yields:
"dmesg | grep -i memory" yields:
"dmesg | grep -i e820" yields:
If I am understanding that last bit correctly the "usables" add up to around 3 GB.
I have a Toshiba Satellite A100-497 (PSAA9E-0P004QSP) with 2 GB of memory that was running Windows XP (horribly at that) and thought it would be a good thing to try Mint. I also thought that it might be fun to try replace the drive with a refurbished SSD. I installed from a DVD using the linuxmint-17.2-cinnamon-64bit.iso image. I only ran into one issue (it seemed to hang on boot with a black screen or a black screen with a cursor) but I solved it by booting into recovery mode and then installing the Nvidia binary driver. So after this everything seemed very pleasing (not that I have played with it very much yet but everything loads fast and everything seems responsive).
So I had this 4 GB of memory lying around and decide it would be great to double the memory (even if it's just to reduce the number of writes to the SSD). I do this and I am not showing the full 4 GB of memory. In fact, it is showing a number that is suspiciously close to the 3 GB limit, 2.9 GB.
BIOS (which is the latest version) shows the laptop to have 4 GB of memory installed and the specifications listed by Toshiba say it can handle a maximum of 4 GB of RAM.
I ran the Memtest86+ test just to see and the result seems peculiar. It recognizes that there are two memory slots with installed memory and it is correctly identified but it is only seeing 3 GB of it, as far as I can tell. See graphic (it's a picture of a laptop screen taken through a webcam so sorry about the low quality):
[rimg]https://farm4.staticflickr.com/3670/197 ... 4cb7_o.png[/rimg]
The graphical System Information application shows the following:
Code: Select all
Operating System Linux Mint 17.2 Cinnamon 64-bit
Cinnamon Version 2.6.11
Linux Kernel 3.16.0-38-generic
Processor Intel© Core™2 CPU T5600 @ 1.83GHz x 2
Memory 2.9 GiB
Hard Drives 120.9 GiB
Graphics Card NVIDIA Corporation G72M [Quadro NVS 110M/GeForce Go 7300]
Oh, and I did consider that some memory might be shared with the video (the BIOS offers no settings dealing with video) but:
- * 1.1 GB seems a little excessive.
* For testing, I reinstalled the original 2 GB & the System Information application showed the expected 2 GB value.
* I believe shared memory should still show up in Memtest86+
Either of the two memory slots works with either of the two memory modules and all four combinations show up as 2 GB of system memory. Having both slots filled and with the order reversed results in 2.9 GB of system memory being shown. So 2 filled slots give 2.9 GB and 1 filled slot gives 2 GB (that is, when it comes to these memory modules, there appears to be no hint of a fault following a piece of hardware).
I did find one example of someone reporting what to me seemed like a similar issue but I'm a bit of a newbie and I can't necessarily make sense of this. Some of the diagnostics they suggested are as follows:
"free -m" yields:
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total used free shared buffers cached
Mem: 3008 2175 832 30 44 802
-/+ buffers/cache: 1327 1680
Swap: 2047 0 2047
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3.16.0-38-generic
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/usr/bin/free: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.24, BuildID[sha1]=cb4ba71f831083ed89fc51dd95e427dade1de0f8, stripped
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# dmidecode 2.12
SMBIOS 2.4 present.
Handle 0x0013, DMI type 16, 15 bytes
Physical Memory Array
Location: System Board Or Motherboard
Use: System Memory
Error Correction Type: None
Maximum Capacity: 2 GB
Error Information Handle: Not Provided
Number Of Devices: 2
Handle 0x0014, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0013
Error Information Handle: No Error
Total Width: 32 bits
Data Width: 32 bits
Size: 2048 MB
Form Factor: SODIMM
Set: 1
Locator: M1
Bank Locator: Bank 0
Type: DDR2
Type Detail: Synchronous
Speed: Unknown
Manufacturer: Not Specified
Serial Number: Not Specified
Asset Tag: Not Specified
Part Number: Not Specified
Handle 0x0015, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0013
Error Information Handle: No Error
Total Width: 32 bits
Data Width: 32 bits
Size: 2048 MB
Form Factor: SODIMM
Set: 1
Locator: M2
Bank Locator: Bank 1
Type: DDR2
Type Detail: Synchronous
Speed: Unknown
Manufacturer: Not Specified
Serial Number: Not Specified
Asset Tag: Not Specified
Part Number: Not Specified
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MemTotal: 3080312 kB
MemFree: 867516 kB
MemAvailable: 1610688 kB
Buffers: 46196 kB
Cached: 822308 kB
SwapCached: 0 kB
Active: 1714684 kB
Inactive: 350608 kB
Active(anon): 1197792 kB
Inactive(anon): 30280 kB
Active(file): 516892 kB
Inactive(file): 320328 kB
Unevictable: 16 kB
Mlocked: 16 kB
SwapTotal: 2097148 kB
SwapFree: 2097148 kB
Dirty: 88 kB
Writeback: 0 kB
AnonPages: 1196816 kB
Mapped: 350432 kB
Shmem: 31288 kB
Slab: 58832 kB
SReclaimable: 37152 kB
SUnreclaim: 21680 kB
KernelStack: 6032 kB
PageTables: 22172 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 3637304 kB
Committed_AS: 3084040 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 317912 kB
VmallocChunk: 34359407612 kB
HardwareCorrupted: 0 kB
AnonHugePages: 274432 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
DirectMap4k: 92608 kB
DirectMap2M: 3051520 kB
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[ 0.000000] Scanning 1 areas for low memory corruption
[ 0.000000] Base memory trampoline at [ffff880000099000] 99000 size 24576
[ 0.000000] init_memory_mapping: [mem 0x00000000-0x000fffff]
[ 0.000000] init_memory_mapping: [mem 0xbfc00000-0xbfdfffff]
[ 0.000000] init_memory_mapping: [mem 0xbc000000-0xbfbfffff]
[ 0.000000] init_memory_mapping: [mem 0x80000000-0xbbffffff]
[ 0.000000] init_memory_mapping: [mem 0x00100000-0x7fffffff]
[ 0.000000] init_memory_mapping: [mem 0xbfe00000-0xbfe6ffff]
[ 0.000000] Early memory node ranges
[ 0.000000] PM: Registered nosave memory: [mem 0x0009f000-0x0009ffff]
[ 0.000000] PM: Registered nosave memory: [mem 0x000a0000-0x000dbfff]
[ 0.000000] PM: Registered nosave memory: [mem 0x000dc000-0x000fffff]
[ 0.000000] Memory: 3049592K/3143736K available (7626K kernel code, 1131K rwdata, 3596K rodata, 1352K init, 1300K bss, 94144K reserved)
[ 0.000000] please try 'cgroup_disable=memory' option if you don't want memory cgroups
[ 0.004042] TOSHIBA Satellite detected - force copy of DSDT to local memory
[ 0.022350] Initializing cgroup subsys memory
[ 0.022660] Freeing SMP alternatives memory: 32K (ffffffff81e6e000 - ffffffff81e76000)
[ 1.240332] Freeing initrd memory: 28280K (ffff8800348b4000 - ffff880036452000)
[ 1.240891] Scanning for low memory corruption every 60 seconds
[ 1.616543] Freeing unused kernel memory: 1352K (ffffffff81d1c000 - ffffffff81e6e000)
[ 1.618921] Freeing unused kernel memory: 556K (ffff880001775000 - ffff880001800000)
[ 1.620977] Freeing unused kernel memory: 500K (ffff880001b83000 - ffff880001c00000)
[ 4.610793] yenta_cardbus 0000:07:06.0: Enabling burst memory read transactions
[ 4.847487] pcmcia_socket pcmcia_socket0: cs: memory probe 0xf0900000-0xf09fffff:
[ 5.611490] pcmcia_socket pcmcia_socket0: cs: memory probe 0x0c0000-0x0fffff:
[ 5.611530] pcmcia_socket pcmcia_socket0: cs: memory probe 0xa0000000-0xa0ffffff:
[ 5.611558] pcmcia_socket pcmcia_socket0: cs: memory probe 0x60000000-0x60ffffff:
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[ 0.000000] e820: BIOS-provided physical RAM map:
[ 0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009f7ff] usable
[ 0.000000] BIOS-e820: [mem 0x000000000009f800-0x000000000009ffff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000000dc000-0x00000000000fffff] reserved
[ 0.000000] BIOS-e820: [mem 0x0000000000100000-0x00000000bfe6ffff] usable
[ 0.000000] BIOS-e820: [mem 0x00000000bfe70000-0x00000000bfefffff] ACPI NVS
[ 0.000000] BIOS-e820: [mem 0x00000000bff00000-0x00000000bfffffff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000fec00000-0x00000000fec0ffff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000fed00000-0x00000000fed003ff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000fed14000-0x00000000fed19fff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000fed1c000-0x00000000fed8ffff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000fee00000-0x00000000fee00fff] reserved
[ 0.000000] BIOS-e820: [mem 0x00000000ff000000-0x00000000ffffffff] reserved
[ 0.000000] e820: update [mem 0x00000000-0x00000fff] usable ==> reserved
[ 0.000000] e820: remove [mem 0x000a0000-0x000fffff] usable
[ 0.000000] e820: last_pfn = 0xbfe70 max_arch_pfn = 0x400000000
[ 0.000000] e820: [mem 0xc0000000-0xfebfffff] available for PCI devices
[ 0.436459] e820: reserve RAM buffer [mem 0x0009f800-0x0009ffff]
[ 0.436462] e820: reserve RAM buffer [mem 0xbfe70000-0xbfffffff]