You find out the style of memory needed and you find out how much memory you have and you find out how many slots the machine has for memory and how many are being used.
Sometimes when all the slots are full you need to replace an existing bank of (small) memory with a new bank of bigger memory.
I have a free utility called "speccy" that informs me of my memory - it say this...
Memory slots
Total memory slots 2
Used memory slots 1
Free memory slots 1
Memory
Type DDR3
Size 2048 MBytes
Channels # Single
DRAM Frequency 398.9 MHz
CAS# Latency (CL) 6 clocks
RAS# to CAS# Delay (tRCD) 6 clocks
RAS# Precharge (tRP) 6 clocks
Cycle Time (tRAS) 15 clocks
Physical Memory
Memory Usage 50 %
Total Physical 1.96 GB
Available Physical 0.98 GB
Total Virtual 7.99 TB
Available Virtual 7.99 TB
SPD
Number Of SPD Modules 1
Slot #1
Memory is relatively cheap - Kingston used to have a "Memory Finder" utility on their web site.
What makes you think you need more memory? If the machine ran OK when it was new and you are not making any excessive demands on it then you probably have another issue rather than insufficient memory - but generally speaking memory is relatively cheap but do not necessarily expect a noticeable increase in performance .
Peccavi, June 2011
