I have posted on another forum in 2 postings that are linked, a few small programs to run to identify the size/type the Chips also links to Purchasing a new card with the Information you have
NOTE Do write it down (long numbers)

Plus on the First link the Program also Shows you on real time whats happening with your CPU/RAM...This also told me I had a dead card(and its location)

And they all tell you the Motherboard (Mainboard)name and CPU Type This is like knowing the Brand and Model of Car you drive.Telling a dealer you want Memory for a "computer" is Very Green. He is going to ask you some questions that'll sound meaningless to you But, having this paper with these numbers will ensure you get the right parts fast