How to determine what type of RAM I need?

I have to upgrade the RAM on 8 different desktop PCs - each of them with varying specs, different ages, different manufacturers, different motherboards, etc. I'm pretty sure they don't all use the same type of RAM.

I've been doing some Googling, and just can't wrap my head around how to determine what type of RAM I will need. I think the main issue is that I don't understand what the different types of RAM are (DDR, DDR2, DDD3, PC400, PC3200), the different speeds, the different physcial sizes (160 pin, 184pin, etc), SIMM, DIMM, DRAM, SDRAM, dual channel, single channel, etc. If you consider the many different permutations that the above can result in, you will understand my predicament.

  1. Is there are good website/online resource that explains modern RAM (ONLY the last 5 years), without explaining all the way back to the 1990s, 1980s or even earlier.

  2. Is there are free tool that I can download to help me determine what type of RAM I need to purchase?

  3. Is there any other advice/suggestions that could be useful/helpful for me to get past this problem.


I've found Crucial's website to be phenomenally useful for this. http://www.crucial.com/uk/. (Other manufacturers may have similar tools). Select your motherboard from the lists and it tells you exactly what it can hold.

Another useful tool for hsowing what you currently have is CPU-Z: http://www.cpuid.com/softwares/cpu-z.html - It'll give you the full breakdown of the RAM you have installed and how many free slots you have.


Try CPU-Z it's a small portable tool used to determine system hardware. Below is a capture of the memory tab.
cpu-z memory
From this you can see what type of RAM is in the machine and what motherboard it has. After you determine the motherboard you can find its manual online and see what other types of RAM it supports and then do some price shopping.


It's best to look at the manual or system documentation from the manufacturer. Another alternative (although slightly less reliable) is to see what a site like crucial.com recommends.

It heavily depends on the process, motherboard and chipset used, so there is no single answer to this.