How to verify if my PC RAM is DDR2 or DDR3

Question

I want to buy a memory expansion for my desktop computer, so I wanted to check if my motherboard supports DDR2 or DDR3. I did some tests for it, but got different results.

1. I ran dmidecode and got this result:

   type=DDR2
   speed=800Mhz
   

2. I saw the words in my mobo and there it clearly said DDR3 near the slot.

3. I saw the specs of my mobo and it said:

   Memory:
   • 2 x DDR2 800/667 MHz SDRAM (8GB max.)
   • 2 x DDR3 1066/800/667 MHz SDRAM (4GB max.)

Another source of confusion is that I have 2 slots in my mobo, but the command shows 4, so I am totally confused about whether I have to buy DDR2 or DDR3 memory.

Answer 1

Run CPU-Z, in the memory tab it shows the RAM type:

Answer 2

I finally found the solution. My Motherboard supports either 4GB of DDR3 or 8GB of DDR2. My currently installed one is DDR2 as said by dmidecode. I can't have one DDR2 and a DDR3. But I can have 2 of either of these.