I put 8gb of ddr3 1600mhz ram into my computer (running ubuntu

Ha ha holy hell. Ddr2 won't even fit in a ddr3 slot. Wtf is your mobo.

>>55772726
Old lenovo thinkcentre desktop. I managed to get it to see the full 8gb but ubuntu is still seeing it as ddr2 clocked at 800mhz. Maybe ubuntu is just being dumb? I'm using lshw to look at my ram.

Command output

*-memory
       description: System Memory
       physical id: 1e
       slot: System board or motherboard
       size: 8GiB
     *-bank:0
          description: DIMM DDR2 Synchronous 800 MHz (1.2 ns)
          product: 000000000000000000000000000000000000
          vendor: Unknown
          physical id: 0
          serial: 00000000
          slot: J6G1
          size: 2GiB
          width: 40960 bits
          clock: 800MHz (1.2ns)
     *-bank:1
          description: DIMM DDR2 Synchronous 800 MHz (1.2 ns)
          product: 000000000000000000000000000000000000
          vendor: Unknown
          physical id: 1
          serial: 00000000
          slot: J6G2
          size: 2GiB
          width: 41472 bits
          clock: 800MHz (1.2ns)
     *-bank:2
          description: DIMM DDR2 Synchronous 800 MHz (1.2 ns)
          product: 000000000000000000000000000000000000
          vendor: Unknown
          physical id: 2
          serial: 00000000
          slot: J6H1
          size: 2GiB
          width: 41984 bits
          clock: 800MHz (1.2ns)
     *-bank:3
          description: DIMM DDR2 Synchronous 800 MHz (1.2 ns)
          product: 000000000000000000000000000000000000
          vendor: Unknown
          physical id: 3
          serial: 00000000
          slot: J6H2
          size: 2GiB
          width: 42496 bits
          clock: 800MHz (1.2ns)

>>55772665
800 MHz is normal, as data is sent both on a rising and a falling edge(hence DDR, Double Data Rate). What you really need to investigate is the DDR2/3 thing.