RAM

can I have 2 RAM chips of differing sizes? (for ex., 1 - 256mbs and 1 - 512 mbs)? I heard a narsty rumor that they had to be the same (i.e. 512mbs+512mbs)

Hey moomoo,

Before I became a Guru of sorts, I worked for six months at one of the largest manufacturers of DRAM memory in the country. Even with my technical background, it amazes me how much knowledge has gone into the DRAM technology, and even as new forms of memory storage hit the market, DRAM still proves to be a reliable form of temporary storage for personal computers.

To answer your question, your computer may be able to support memory of different sizes, however MOST computers do not. I recommend that you use memory from the same manufacturer and of the same size. There are other variables involved other than the memory size that dictate what type of memory you should use. I will give you a little bit of information about why you should not use different sizes.

In the past few years, there has been alot of development in the DRAM market. Two years ago the memory of choice was DDR DRAM memory and DDR2 memory had just hit the market. Today, DDR2 is alot more prevelent, and now DDR3 is coming to the market. These different different types of memory operate at different speeds, and voltages. Remember, your computer is only as fast as your slowest link.

Say you have a computer with 512 PC2-3200 (i.e. 200MHz) DDR2 Memory and you decide you want to upgrade to a 1 GB. You go out and find a PC2-8000(i.e. 500MHz) DDR2 memory module on sale, and purchase it. You open your case to install it, and you notice there is one open slot. Well you say to yourself, "why, if i install this new RAM, and keep the old one in there, I will have 1512 MB of memory!" Well, IF your computer supports memory of different sizes, yes, you will increase your DRAM size, but the maximum operating speed will only be as fast as your slowest link, which in this case is the old PC2-3200 speed.

In other words, you will not notice any increase in speed or performance by mixing memory types. In some cases you will see the computer load slower, depending on how the operating system handles memory mapping. My advice is to consult with the manufacturer of your PC or motherboard before you upgrade. :wink:

Hope that helps!
Good Luck!!!