Instant Expert: RAM

If your notebook isn’t running as fast as when you first purchased it, an insignificant amount of RAM (random access memory) may be the culprit. On most systems it’s easy to upgrade or configure your notebook with at least 3GB, and it will breathe easy as you plow through your documents, spreadsheets, applications, and multimedia files; skimp on it, and your notebook will suffer from sluggish performance. In fact, we’d argue that RAM is more important than processor speed, and Mark Tekunoff, senior technology manager at Kingston, would agree. We spoke to him for the lowdown on one of the most vital computer components.

LAPTOP: What is RAM?
Mark Tekunoff: RAM is the location where your computer stores information that will be accessed by the CPU. The more RAM that’s added reduces the number of times that the CPU must read data from the hard drive, resulting in faster performance. RAM is volatile, so any information stored within it will disappear as soon as you turn the computer off.

How much RAM is needed to keep a notebook running smoothly?
We recommend a minimum of 2GB for Mac OS X Leopard and Windows Vista, but power users that edit video or play high-end games like Crysis should never have less than 3GB or 4GB of RAM. Netbooks and other systems powered by Windows XP and Linux operating systems can make do with 1GB of RAM.

What’s the difference between DDR2 and DDR3 RAM?
RAM comes in three varieties: Double Data Rate 1, 2, and 3. DDR1 RAM features speeds that range from 266 MHz to 400 MHz, while swifter DDR2 and the newest DDR3 RAM operate at 400 MHz to 800 MHz and 800 MHz to 1.6 GHz, respectively. With the improved performance comes a premium. [Newegg.com, a popular online computer supply store, sells Corsair’s 2GB DDR3 kit (consisting of two 1GB sticks) for $90, while a 4GB DDR2 kit (consisting of two 2GB sticks) sells for $69.]

What’s the typical maximum amount of RAM that can be installed in a notebook?
The BIOS software that boots notebooks running 32-bit operating systems (the most common retail version of Mac OS X and Windows) was written years ago when 4GB of memory was seen as a far-off limit and, as such, these systems don’t recognize more than 3GB to 3.6GB. Sixty-four–bit operating systems have no such limit, and because of that, they can utilize 4GB or more of RAM. However, applications have to be specifically written to take advantage of over 4GB of RAM.

Why don’t some notebooks recognize a full 4GB of RAM?
Graphics drivers, USB drivers, and other underlying software is often loaded on the top end of RAM memory, which cuts into the full storage capacity available for use in 32-bit operating systems. Thus, a typical system will only see between 3GB and 3.6GB of memory. When 64-bit operating systems and their related applications become far more widespread and accessible, systems will be able to utilize the maximum
RAM available.

Is it better to have RAM installed in one slot or equally distributed between two slots?
Modern computers use a dual-channel architecture, which is really just a fancy way of stating that information is streamed down two separate pipes, thus increasing the amount of data bandwidth. If you only have one stick of memory, however, or a mixed configuration of 1GB and 2GB combined, then it will generally run in a lower-performing, single-channel memory mode.

Having RAM distributed over two slots can certainly save money. A single 2GB module uses two gigabits of chip density (the amount of memory cells); two 1GB modules typically have one gigabit of chip density, which is cheaper. It should be noted that two modules use slightly more power but have no significant impact on battery life. The only advantage to having RAM occupy one slot is that if you opt to add more memory, all you have to do is pop a stick into the vacant slot; there’s nothing to remove.

Is it more cost-efficient to purchase RAM through a notebook vendor or install it yourself?
Although it’s convenient to pack your notebook with extra RAM while you’re configuring a notebook online, you can save a nice chunk of money by adding more yourself. [For example, as of this writing the lowest-end Dell Studio 15 notebook ($599) includes 2GB of RAM, which you can upgrade to 4GB for an additional $100. However, you can purchase a 4GB kit of Corsair DDR2 RAM for $55—a savings of $45.