One final thing, especially when you're building your own machine, make sure your RAM isn't too big. I suspect it could be 'more is better' enabling the RAM to work together. Regarding capacity, I don't really know if it's better to have 1x4GB or 2x2GB, or 2x8 or 4x4GB. Dual-channel motherboard, with color indication of slots. As I have two modules, it goes in 1 and 3 and if I had 4 modules the other two modules would go in 2 and 4. Machines with dual-channel RAM slots (as mine is) need to be installed in pairs for better performance, so if I had one RAM module, it would go in slot 1. My aforementioned M5A9 has 4 slots, named 1, 2, 3, and 4 (just for explanation). It's important to note that you can't chuck in any mixture of RAM sizes and specs or slots. Again, this is only used in servers and you wouldn't need to buy ECC RAM for a desktop board. RAM for servers does pretty much the same, although it has a feature called ECC which is Error Checking Code which checks the data to ensure data integrity. In most cases, I wouldn't worry about this too much, buy the same what you already have. Faster RAM tends to be more expensive too. The higher the number, the faster the RAM is. RAM has latency that you have to worry about as well. It can support up to 32GB of RAM, consisting of 4x 8GB DDR3 RAM modules. The manual which came with it (plus the spec sheet on the site, and the box) showed the boards capabilities. My motherboard in my desktop at home is an Asus M5A9 R2.0. When buying RAM you need, as said, to look at Capacity (1, 2, 4, 8GB) number of modules in the kit (1, 2, etc) and the timings. Middle: DDR2 without heat spreader, Laptop DDR2, Bottom (OLD) Desktop DDR, Laptop PC-100

From Wikipedia: Top: DDR2 with heat spreader. Recent machines will typically have DDR2 or DDR3 RAM, and can come in various shapes, sizes and form factors (RAM for Laptops and micro machines is a smaller size of board). These programs will tell you what size, speed/frequency and specification of RAM you have. Speccy from Piriform and Aida32/64 which was previously Everest. You can either look up your motherboard manual online or use a system information tool.

What slot does the ram go in