How to check RAM details
Page will be interest those who want to find information regarding what RAM exists on their system and what compatible upgrades they can get. Examples below were run on a Dell PowerEdge R620 host, mem.
Finding out how much RAM you can get
Use dmidecode -t memory | less to see useful information regarding what your computer can be upgraded to and what currently exists on your system.
The first section of the output will show you what sort of memory to use, the maximum memory you can install, and the number of RAM sticks you can use.
dmidecode -t memory Handle 0x1000, DMI type 16, 23 bytes Physical Memory Array Location: System Board Or Motherboard Use: System Memory Error Correction Type: Multi-bit ECC Maximum Capacity: 768 GB Error Information Handle: Not Provided Number Of Devices: 24
From this output, we can see that the RAM sticks this motherboard supports are registered ECC (as is common with most servers). It supports a maximum of 768 GB over 24 slots which comes down to 32GB per slot. I know that this host has 2 processors which are Xeon E5-2680. If you look up the processor, you can see that each processor supports up to 384 GB RAM. So, 768 GB for the whole machine makes sense.
The next section of the dmidecode output show what exists in each slot. The output here corresponds to ram slot with an 8GB DDR3 stick from Hynix:
# Below information we can see total width is 8 bits bigger than data width which indicates it is ECC memory (the additional 8 bits are designed for error correction checking). # It has a size of 8192 MB indicating 8 GB. # It's DDR3 SDRAM that runs at 1600 MHz. # The manufacturer name sometimes shows up as an actual company name (ie Samsung/Crucial/Kingston) but sometimes it comes out as gibberish like below # Searching the part number online will usually yield the actual product Handle 0x1100, DMI type 17, 34 bytes Memory Device Array Handle: 0x1000 Error Information Handle: Not Provided Total Width: 72 bits Data Width: 64 bits Size: 8192 MB Form Factor: DIMM Set: 1 Locator: DIMM_A1 Bank Locator: Not Specified Type: DDR3 Type Detail: Synchronous Registered (Buffered) Speed: 1600 MHz Manufacturer: 00AD00B300AD Serial Number: 35AB5CF9 Asset Tag: 01124263 Part Number: HMT31GR7CFR4C-PB Rank: 2 Configured Clock Speed: 1600 MHz
If the RAM slot is empty, it will look like this:
# (Empty RAM Slot) Handle 0x1108, DMI type 17, 34 bytes Memory Device Array Handle: 0x1000 Error Information Handle: Not Provided Total Width: 72 bits Data Width: 64 bits Size: No Module Installed Form Factor: DIMM Set: 3 Locator: DIMM_A9 Bank Locator: Not Specified Type: DDR3 Type Detail: Synchronous Speed: Unknown Manufacturer: Serial Number: Asset Tag: Part Number: Rank: Unknown Configured Clock Speed: Unknown