Samsung PC-2100 (DDR-266) Bus Speed Computer RAM 1 GB Capacity per Module

How RAM Speed Matters

Computer memory is one of those things that you really notice when you don't have enough in your system. Everything bogs down as both you and the CPU wait for the hard drive to dredge up the data you need.

What is DDR?

DDR RAM was a reaction to the fact that while processor speeds were increasing, the existing 64-bit memory bus was running into stability issues when they tried to push it past 133 MHz. It's a simple problem, the wider the connection the more traces you have to manage and the more difficult it is to increase the frequency. Going to DDR sidestepped the problem; rather than increasing the base frequency, it doubled the bandwidth by transferring two bits of data on every tick of the clock for an effective speed of 266 MHz. There are a few other differences between double data rate and SDRAM that were necessary to make it happen:

• Packaging: It comes in a 184-pin DDR DIMM as opposed to the 168-pin DIMM used for SDRAM. This ensures that you can't put the wrong module in memory slot.
• Voltage: DDR dropped the voltage to 2.5 Volts from 3.3 Volts.

How Much RAM Should You Install?

The simplest answer to the question of how much RAM to install is based entirely on your motherboard: as much as it will support. Having 2 GB of memory is going to make your system run much more smoothly than having 1 GB of RAM because of the nature of operating systems. Every OS has a footprint; it uses some of your RAM for itself so that it can run your existing applications. Adding another GB of Samsung RAM means that the increased capacity can go directly to application support because you are already covering your OS. There are however a few things that you do have to consider first:

• OS Support: 32-Bit Windows can only support a maximum of 4 GB so that limits your options unless you have a 64-bit OS.
• Motherboard Support: Many system boards have two limits for RAM; the number of physical slots and the capacity of the modules each slot supports. Your system maximum will be the combination of the two.

Choosing RAM

One thing that helps when looking for several GB of RAM is to pick a reputable brand name such as Samsung. You should also check whether your system uses a single-channel or dual-channel setup as it may be more effective to get two smaller modules than one large one so that you can populate both channels for higher transfer rates. Choosing components is as much an art as a science, but once you find the DIMMs you need, the results will be significant.