Windows 7 reports 32Gb of memory Linux/knoppix doesn't ...

[Albretch]

I got the change to use a test box with 32 Gb of RAM, but when I start it knoopix, this is what it apparently sees:
~

total used free shared buffers cached
Mem: 3371052 324132 3046920 0 5728 202496
-/+ buffers/cache: 115908 3255144
Swap: 0 0 0

~
based on the cheat codes
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http://www.knoppix.net/wiki/Cheat_Codes
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you must enter mem as Megabytes, but should I use mem={32G, 32000M, or 32678M}?
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also I notice memtest is apparently not working
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Is there aquick fix for that? What would you suggest?
~
thanks
lbrtchx

[klaus2008]

I would suggest that you use Knoppix V6.7.1 DVD and issue
knoppix64 at the boot prompt. The usual Knoppix Linux kernel does not handle more than 4 GB RAM, but the 64-bits Linux kernel should see all the memory.

[Albretch]

knoppix64
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was it, but I still can't figure out how to run a memtest from the command prompt.
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how do you run memtest? Nothing seems to happen when you try:
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boot: memtest
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All I see is a blank screen
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lbrtchx

[klaus2008]

You could download Memtest86 (http://www.memtest86.com/) from this (http://www.memtest86.com/download.html) page. As you will see there are two different versions available. Versions 4.0b was created for servers with up to 32 cores and up to 8 TB of memory.

[Albretch]

OK, I downloaded and burned memtest86 Version 4.0b (Server) (26-Oct-2011) onto a CD, but when I boot up the box with the CD all I see is:
~


Memtest86 Version 4.0b Server
-----------------------------

Select Version:

1) Boot V4.0b Server (Default)

2) Boot V4.0a

3) Boot V3.5b

boot: 1
Loading memtest.....ready.
~
I don't see any progress screen or anything and when I run dmidecode in my system I see a long listing, which memory related information is encoded in chunks that look like this:
~
Does it relate to memtest not running?
~


# dmidecode 2.9
SMBIOS 2.5 present.
82 structures occupying 2627 bytes.
...
Handle 0x0036, DMI type 16, 15 bytes
Physical Memory Array
Location: System Board Or Motherboard
Use: System Memory
Error Correction Type: Multi-bit ECC
Maximum Capacity: 64 GB
Error Information Handle: Not Provided
Number Of Devices: 8

Handle 0x0038, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0036
Error Information Handle: Not Provided
Total Width: 72 bits
Data Width: 64 bits
Size: 4096 MB
Form Factor: FB-DIMM
Set: 1
Locator: DIMM01
Bank Locator: Not Specified
Type: DDR2 FB-DIMM
Type Detail: Synchronous
Speed: 667 MHz (1.5 ns)
Manufacturer: <...>
Serial Number: <...>
Asset Tag: Not Specified
Part Number:

Handle 0x0042, DMI type 19, 15 bytes
Memory Array Mapped Address
Starting Address: 0x00000000000
Ending Address: 0x0082FFFFFFF
Range Size: 33536 MB
Physical Array Handle: 0x0036
Partition Width: 0

Handle 0x0048, DMI type 20, 19 bytes
Memory Device Mapped Address
Starting Address: 0x00430000000
Ending Address: 0x0052FFFFFFF
Range Size: 4 GB
Physical Device Handle: 0x003C
Memory Array Mapped Address Handle: 0x0042
Partition Row Position: 4

[Albretch]

// __ http://mirror.its.uidaho.edu/pub/ubuntu-releases/oneiric/
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DVD version of unbuntu (AMD is used for Intel x86 as well)
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it is a displayed boot option ("test memory")
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lbrtchx

[klaus2008]

If Memtest86 doews not work on your system you could try Memtest86+ (http://www.memtest.org). There is a download section (http://www.memtest.org/#downiso) on the web page with a pre-compiled bootable ISO.