I have just added 128mb memory to my vaio pcg-F801A lap top computer it has 64mb chip in one bay I put the 128mb in the other. The problem I have is the 128mb chip only gets recognised as 64mb whether it is in either bay or on its own or together with the original 64mb chip I have taken chip back to shop and they have given me a replacement, but still the same, so I know the memory is ok, according to my book work the computer should be upgradeable to 256mb Has anybody any idea's ---- Thanks
Older motherboards cannot address the full capacity of newer RAM modules, as they are short of an addressing line. Thus you see only half the capacity of the module.
You need what is commonly termed a "double-sided" RAM module. I have had exactly this problem with such a system, and it is a common problem with sytems around three years old, and more.
You must get the correct type of module - the easy way to ensure this is to get one specifically sold to upgrade your particular system, or buy from a manufacturer such as Crucila, who will guarantee to get you the correct type of module.