These different types of RAM come in varying ‘form factors’, or packaging styles; that is, the physical size, number of pins, and so forth varies from one type to another. They also differ in voltage ratings and capacity. Thus, different kinds of RAM cannot be mixed and matched. In fact, the motherboard is generally built to support only one type of memory, and different kinds of RAM will not even fit in the same sockets. In most cases, you can’t even mix modules with different capacities, although Intel does have a chipset for DDR2 that allows for mixing of different module sizes.
So before you replace or upgrade the RAM in your computer, you need to determine what type, speed, and the maximum capacity your motherboard can support. There are a couple of different ways to make this determination:
Crucial is a manufacturer of high quality memory, and the Memory Advisor tool is easy to use. You simply plug in your computer system information (manufacturer and model), and you’ll receive several recommendations for compatible memory. Of course, they hope that you’ll purchase your RAM from them, but you are also provided with the specifications of the RAM that is compatible with your system, so you can purchase from another vendor if you so choose.
If for some reason you don’t know the details about your computer needed to use the Memory Advisor tool, you can use the System Scanner tool, available on the same web page. This tool will scan your system and tell you what type of RAM is already installed in your system, and will then make recommendations for memory that is compatible with your system.
Bear in mind that if you simply pull out your RAM and take it in to a local vendor to match it, you’ll likely get memory modules that will physically fit in your system, but will not necessarily have the same voltage and speed specifications.
There are a few other issues you’ll need to consider before buying RAM. First, you need to determine if there are any open memory sockets on the motherboard. If the sockets are ‘fully populated’, you’ll have to replace your current RAM with higher capacity modules. Keep in mind that it might be more cost effective to purchase one large-capacity module than say, two smaller ones.
When adding RAM, you also need to match the metal type of the RAM module with that of the memory socket on the motherboard. There are two types available: tin and gold. Over time, direct contact between two dissimilar metals can cause an oxidizing chemical reaction, so you must make sure that you use gold memory modules in gold sockets and tin modules in tin sockets. Because most modern computers use gold contacts, it’s not as much of a problem as it once was, but worth being aware of nonetheless.
In sum, the key to a successful memory upgrade is to be properly prepared with the information we’ve covered here. And now, on to the upgrade procedure (which is the easy part!). First, a few precautionary notes:
Precautions: