To find out what kind of RAM you have on your computer, just run the following command:

dmidecode ?type 17

The output I get when I run the command on my HP TM2 laptop is as follows:

# dmidecode 2.11
SMBIOS 2.6 present.

Handle 0x0014, DMI type 17, 28 bytes
Memory Device
        Array Handle: 0x0013
        Error Information Handle: Not Provided
        Total Width: 64 bits
        Data Width: 64 bits
        Size: 2048 MB
        Form Factor: SODIMM
        Set: None
        Locator: Bottom-Slot 1 (left)
        Bank Locator: BANK 0
        Type: DDR3
        Type Detail: Synchronous
        Speed: 800 MHz
        Manufacturer: Hynix
        Serial Number: 22718C96
        Asset Tag: Not Specified
        Part Number: HMT125S6BFR8C-H9
        Rank: 2

Handle 0x0016, DMI type 17, 28 bytes
Memory Device
        Array Handle: 0x0013
        Error Information Handle: Not Provided
        Total Width: 64 bits
        Data Width: 64 bits
        Size: 2048 MB
        Form Factor: SODIMM
        Set: None
        Locator: Bottom-Slot 2 (right)
        Bank Locator: BANK 2
        Type: DDR3
        Type Detail: Synchronous
        Speed: 800 MHz
        Manufacturer: Hynix
        Serial Number: 22718C8D
        Asset Tag: Not Specified
        Part Number: HMT125S6BFR8C-H9
        Rank: 2