topic Re: how to know about the Memory type in Operating System - Linux

how to know about the Memory type

Maaz — Mon, 09 Mar 2009 10:10:37 GMT

OS: SLES 10 SP 2

how do I know, if the memory is 'DDR' or 'DDR 2' ?

neither "hwinfo --memory" nor "cat /proc/meminfo" informs about the type of installed memory ?

Regards

Re: how to know about the Memory type

Ivan Ferreira — Mon, 09 Mar 2009 11:56:19 GMT

In some cases, you can identify that information with dmidecode:

http://linuxator.wordpress.com/2008/10/28/using-dmidecode-to-find-out-what-memory-chips-you-have/

Re: how to know about the Memory type

Steven E. Protter — Mon, 09 Mar 2009 13:34:45 GMT

Shalom,

Best bet is to look up the specifications on the server hardware.

SEP

Re: how to know about the Memory type

Matti_Kurkela — Tue, 10 Mar 2009 09:02:33 GMT

If you have the lm_sensors software installed and configured, you can usually use the included "decode-dimms.pl" script to get very detailed information about your memory modules. You'd want to check the "Fundamental Memory type" reported by the script.

For lm_sensors to be able to read your memory module information, your hardware must contain a supported i2c controller (usually integrated in the motherboard chipset). You'll have to load a few kernel modules: at least "i2c_core", "eeprom" and the driver module for your i2c controller.

The lm_sensors software is included in most Linux distributions, so it can usually be installed using the package manager of your distribution. It might even be installed by default, but not configured automatically. To configure it, run "sensors-detect" as root.

MK

Re: how to know about the Memory type

Ciro Iriarte — Tue, 10 Mar 2009 14:32:10 GMT

Try with:

hwinfo --bios|grep -A8 "Memory Device:"

or

dmidecode |grep -B12 "Memory Device$"

Re: how to know about the Memory type

Maaz — Fri, 13 Mar 2009 07:09:29 GMT

Thanks everyone for nice and excellent help

the following output means that I can install max 8 memory sticks. and the max size of each memory stick could be 8 GB.
right or wrong ?

# dmidecode -t 16
# dmidecode 2.7
SMBIOS 2.3 present.

Handle 0x1000, DMI type 16, 15 bytes.
Physical Memory Array
Location: System Board Or Motherboard
Use: System Memory
Error Correction Type: Single-bit ECC
Maximum Capacity: 64 GB
Error Information Handle: Not Provided
Number Of Devices: 8
------

on the same machine, I ran
# dmidecode -t 17

Handle 0x1100, DMI type 17, 27 bytes.
Memory Device
Total Width: 72 bits
Data Width: 64 bits
Form Factor:
Set: None
Type:

I posted the selected output only.

what is the meaning of the following
Total Width: 72 bits
Data Width: 64 bits

and why its saying
Type:

while on another machine, when I ran "dmidecode -t 17", I got the following output
Type: DDR2

Regards

Re: how to know about the Memory type

Maaz — Fri, 13 Mar 2009 09:32:21 GMT

and one more thing to ask

why dmidecode is reporting wrong Type of Memory on some machines ?

on a Desktop class machine(Dell OPTIPLEX GX520) when I ran
# dmidecode -t 17
Type: DDR
Type Detail: Synchronous
Speed: 533 MHz (1.9 ns)

i.e Type is "DDR" and not the "DDR2", while I know that this machines has 2 "DDR2" memory sticks installed.

dmidecode is reporting wrong type i.e instead of "DDR2", it shows "DDR"

and yes on the same machine, "decode-dimms.pl" reports the TYPE as "DDR2", which is true/right.

# decode-dimms.pl
Fundamental Memory type DDR2 SDRAM

"decode-dimms.pl" wins ;)

Regards