What is RAM
RAM stands for Random Access Memory. It is a kind of storage where the computer, mobile phone or even graphics card can store information while it uses it. There are a lot of types of RAM. A few examples are: DDR3, DDR2, SD-RAM, and of most of all the types, there are so-called SO-DIMMs, which stands for Small Outline Dual In-line Memory Module. SO-DIMMs are are smaller than normal modules and are therefore mostly used in laptops, but also in a lot of small desktops or all-in-one desktops like Apple’s iMac’s.
The advantage of RAM is that it is fast, and that it can access any piece of data at any place(address) with approximately the same speed. The disadvantage of RAM is that it needs power to maintain the data. Because this is the main source where the data you are working with is stored, you want fast RAM, so that the data stored in the RAM can be accessed as fast as possible. Also, if you have more RAM, your computer can keep more relevant files in it, and therefore works faster because it doesn’t need to access the disk for every file it needs. But, RAM is generally not the best part to put a lot of money in. For most people, 4 to 8GB of DDR3 RAM, running at 1333 or 1600Mhz in Dual-Channel is more than enough, just make sure you have a good brand, like Corsair or G.Skill. It gives you more speed to go with a decent CPU and an SSD, than to spend all your money on 16GB of 1866Mhz memory, which you won’t use anyway. Unless you are an audio or video-editor of course.
So, RAM significantly improves your system’s speed by containing the OS and applications you are running, but don’t overdo things. If you wan’t just that little bit of extra performance, make sure you memory has good timings. They are often refered to as CAS latency. This is the time in clockcycles that is between the request of a certain data-address, and the point at which the data is actually available at the module’s output pins. So, lower is better. For example, DDR3 memory at 1600Mhz with very tight timings(7 is good for DDR3@1600Mhz), can outperform a module running at 1866Mhz, with very high latency. Note that memory with good timings will cost you a little more.