How to select a computer main memory

What is a computer memory? Contrary to the popular belief, the term computer memory includes not just the computer's main memory, so popularly known as the RAM but aslo includes other memory modules available in the microprocessor,motherboard, your video card and so on and even your hard disk, but it is more popular as the secondary memory.


Before we get to the business of selecting the RAM for your computer, lets get familiar about computer memory and the various types available.

So what is RAM anyway? RAM stands for Random Access Memory. Mark the Random - it means that the memory, unlike the other versions of electronic memory that we know of, like the tape or the hard disk, doesnt need to search for data sequentially. In other words, the time required to obtain any data remains the same regardless of its location.
The first and most important characteristic of RAM is that it is fast.
The second characteristic of the Random Access Memory(RAM) is that it is volatile. Which essentially means - no power, no memory.

Why do we need a computer main memory in the first place?
The microprocessor of your computer is slowed up by rate at which data is transferred to it. In the absence of a computer main memory, the data rate goes down even further, thus resulting in undermining the true potential of the processor.

How does the computer memory - main memory that is, differ from the other types of RAM available on the various chips? High speed RAM is found on various parts, like the microprocessor itself - e.g. L1 cache - What is that?
The microprocessor requires a high speed memory area wherein the instructions and data can be held – that’s the L1 cache (For the Intel Core 2 Duo E6700, the L1 cache is 128 KB). Apart from that, there is its more popular level, the L2 Cache – That holds the instructions that might be used shortly (For the aforementioned processor, it is 4 MB). Now, the same memory, if available on the motherboard is classified as the L3 cache.
So much for the various types of computer memory. And again, we haven’t touched on the memory available on the video cards/graphics adapters and the like.

(All that is fine, but what about the jargon, DDR, SDRAM, DDR2 and the like?) Lets cut the history and get ahead with SDRAM first. SDR SDRAM stands for Single Data Rate Synchronous Dynamic RAM.
“Synchronous” because it operates at the system bus speed.
DDR SDRAM – The DDR stands for “Double Data Rate”. Hence, it operates at double the speed of SDR SDRAM and hence doubles up as the most popular form of computer memory.
The higher version of DDR, the DDR2 has already dominated the memory market despite some competition from RDRAM (Direct Rambus) - which died down over time. Now of course, a DDR2 and its successors rule the computer main memory market.

Getting to the part of selecting the computer main memory –

1. What system are you using? As much as it sounds funny, RAM incompatibility with motherboard needs to be verified, especially if you plan to upgrade your system’s main memory.
2. What is your operating system? As the complexity of the OS increases, the RAM requirement goes along with it. Currently Windows Vista shows good performance with a 1 GB memory than with lower ones.
3. What programs do you intend to use? If you are the compulsive gamer type, or use high memory applications like simulations, graphics processing etc, you definitely need higher computer main memory. 2GB for most high profile simulations is the norm.
4. Pricing – Higher priced RAMs are priced higher than other main memory counterparts because of the stringent testing they go through, the density they possess and higher temperature capacity. Betting on the high priced memory modules is a pretty safe option.

As for the future of computer main memory, there is the Z-RAM with its high density and capacitor-less bit configuration, which should offer much more powerful options than the memory modules available today.