Why can I not find my RAM specs through software?

TheFeline123456789 · 09-11-2023, 05:39 PM

I wanted to find the RAM specs such as frequency and interleaving. Here's a few things I tried:

Code:

username@username-T400:~$ sudo lshw -c memory
[sudo] password for username: 
  *-firmware                
       description: BIOS
       vendor: coreboot
       physical id: 0
       version: CBET4000 20211122
       date: 11/22/2021
       size: 1MiB
       capacity: 8MiB
       capabilities: pci pcmcia upgrade bootselect acpi
  *-cache
       description: L2 cache
       physical id: 7
       slot: CACHE2
       size: 6MiB
       capacity: 6MiB
       capabilities: internal unified
       configuration: level=2
  *-memory
       description: System memory
       physical id: 1
       size: 7936MiB

Code:

username@username-T400:~$ sudo hwinfo --memory
01: None 00.0: 10102 Main Memory                                
  [Created at memory.74]
  Unique ID: rdCR.CxwsZFjVASF
  Hardware Class: memory
  Model: "Main Memory"
  Memory Range: 0x00000000-0x1d9d69fff (rw)
  Memory Size: 7 GB + 512 MB
  Config Status: cfg=new, avail=yes, need=no, active=unknown

Code:

username@username-T400:~$ sudo dmidecode -t 17
# dmidecode 3.3
Getting SMBIOS data from sysfs.
SMBIOS 3.0 present.

My gut tells me it's the fault of Libreboot. If so, I'd enjoy an explanation as my search engine skills fail me.
Ended up opening the laptop and looking at the stickers on the RAM.

frankbell · 09-11-2023, 09:05 PM

Have you tried lscpu?

Jan K. · 09-12-2023, 02:25 AM

inxi no good?

business_kid · 09-12-2023, 04:02 PM

Quote:

Originally Posted by TheFeline123456789

I wanted to find the RAM specs such as frequency and interleaving. Here's a few things I tried:

You won't get that from software. I open up, read the chip numbers from the little rectangles of black plastic, and read the datasheet from them. You also get words of wisdom online from hardware geeks that save you decoding the engineering gobbledygook.

That datasheet gets you the DRAM. Now there's L1 and L2 caches to find out about also. Unless you're designing hardware, you don't need any of this stuff. If you are designing hardware, you need to study Application notes and datasheets.

obobskivich · 09-12-2023, 10:41 PM

I don't have any experience with libreboot to say one way or another, but this is one area where linux is deficient compared to Windows, where utilities like CPU-Z and AIDA64 can give you a wealth of information about installed memory (including, in many cases, IC information and serial numbers, without ever opening the case). If you can't get anything meaningful out of dmidecode or lshw you will probably have to open the case up and take a look. I have not ever found a reliable method of actually determining if the system is running in single/dual/triple channel in linux - the general suggestion is to look at dmidecode output and if it shows 'bank 1' and 'bank 2' and so on just assume it is, but that isn't always accurate (especially for some older motherboards where the channel assignments aren't intuitive, or if you're filling out a server with many DIMM slots, or if you're doing an asymmetric configuration, etc) - the 'dirty' way of doing it is to use openbenchmarking's memory bandwidth test against different configurations of the DIMMs and see what impact their position has on bandwidth...or load Windows and use CPU-Z or AIDA64. Some motherboard BIOSes can also give you most/all of this information, especially on newer boards.