Cómo saber si mi PC necesita más memoria ram

Info del cpu,¿es 32 o 62 bits?:

 

$ sudo lshw -class processor
 

 Rápido info de memoria usada, libre, caché y swap

 $ free -m

Info sobre la ram, tipo, capacidad , máximo que acepta la placa base: 

 Asus :

$ sudo dmidecode --type memory
 

 # dmidecode 3.2
Getting SMBIOS data from sysfs.
SMBIOS 2.4 present.

Handle 0x0008, DMI type 5, 20 bytes
Memory Controller Information
    Error Detecting Method: None
    Error Correcting Capabilities:
        None
    Supported Interleave: One-way Interleave
    Current Interleave: One-way Interleave
    Maximum Memory Module Size: 4096 MB
    Maximum Total Memory Size: 8192 MB
    Supported Speeds:
        Other
    Supported Memory Types:
        DIMM
        SDRAM
    Memory Module Voltage: 3.3 V
    Associated Memory Slots: 2
        0x0009
        0x000A
    Enabled Error Correcting Capabilities:
        None

Handle 0x0009, DMI type 6, 12 bytes
Memory Module Information
    Socket Designation: DIMM A1
    Bank Connections: 0 1
    Current Speed: 30 ns
    Type: DIMM SDRAM
    Installed Size: 1024 MB (Double-bank Connection)
    Enabled Size: 1024 MB (Double-bank Connection)
    Error Status: OK

Handle 0x000A, DMI type 6, 12 bytes
Memory Module Information
    Socket Designation: DIMM B1
    Bank Connections: 2 3
    Current Speed: Unknown
    Type: DIMM SDRAM
    Installed Size: Not Installed
    Enabled Size: Not Installed
    Error Status: OK

Handle 0x002D, DMI type 16, 15 bytes
Physical Memory Array
    Location: System Board Or Motherboard
    Use: System Memory
    Error Correction Type: None
    Maximum Capacity: 4 GB
    Error Information Handle: Not Provided
    Number Of Devices: 2

Handle 0x002F, DMI type 17, 27 bytes
Memory Device
    Array Handle: 0x002D
    Error Information Handle: Not Provided
    Total Width: 64 bits
    Data Width: 64 bits
    Size: 1024 MB
    Form Factor: DIMM
    Set: None
    Locator: DIMM A1
    Bank Locator: BANK0
    Type: DDR2
    Type Detail: Synchronous
    Speed: 667 MT/s
    Manufacturer: Manufacturer0
    Serial Number: SerNum0
    Asset Tag: AssetTagNum0
    Part Number: PartNum0

Handle 0x0031, DMI type 17, 27 bytes
Memory Device
    Array Handle: 0x002D
    Error Information Handle: Not Provided
    Total Width: Unknown
    Data Width: Unknown
    Size: No Module Installed
    Form Factor: DIMM
    Set: None
    Locator: DIMM B1
    Bank Locator: BANK1
    Type: Unknown
    Type Detail: Unknown
    Speed: Unknown
    Manufacturer: Manufacturer1
    Serial Number: SerNum1
    Asset Tag: AssetTagNum1
    Part Number: PartNum1

Acer extensa 5230

# dmidecode 3.2
Getting SMBIOS data from sysfs.
SMBIOS 2.5 present.

Handle 0x0015, DMI type 16, 15 bytes
Physical Memory Array
    Location: System Board Or Motherboard
    Use: System Memory
    Error Correction Type: None
    Maximum Capacity: 4 GB
    Error Information Handle: Not Provided
    Number Of Devices: 2

Handle 0x0016, DMI type 17, 27 bytes
Memory Device
    Array Handle: 0x0015
    Error Information Handle: No Error
    Total Width: 64 bits
    Data Width: 64 bits
    Size: 1024 MB
    Form Factor: SODIMM
    Set: 1
    Locator: M1
    Bank Locator: Bank 0
    Type: DDR2
    Type Detail: Synchronous
    Speed: 667 MT/s
    Manufacturer: Mfg 0
    Serial Number: 1234-B0
    Asset Tag: Not Specified
    Part Number: SODIMM000

Handle 0x0017, DMI type 17, 27 bytes
Memory Device
    Array Handle: 0x0015
    Error Information Handle: No Error
    Total Width: 64 bits
    Data Width: 64 bits
    Size: 1024 MB
    Form Factor: SODIMM
    Set: 1
    Locator: M2
    Bank Locator: Bank 1
    Type: DDR2
    Type Detail: Synchronous
    Speed: 667 MT/s
    Manufacturer: Mfg 1
    Serial Number: 1234-B1
    Asset Tag: Not Specified
    Part Number: SODIMM001