PC2-8500 (DDR2-1066) Bus Speed Computer RAM 2 GB Capacity per Module 2 Modules

Choosing the Right RAM for a Computer

When your PC falls into a cycle of slow responses when working on multiple programs, changing parts of the hardware might help to fix the problem. The random access memory (RAM) is a temporary storage unit that helps the computer access data quicker than it would have done from the hard drive. It is possible to expand the RAM on your computer as long as the hardware supports it.

How do I know if I have the right type?

There are two basic types of RAM.

• Dynamic RAM (DRAM) - The electrical components in this RAM continuously release energy, making it necessary to keep refreshing the system.
• Static RAM (SRAM) - It relies on a continuous flow of electrical energy, cutting the need to keep refreshing the system.

Since the SRAM does not release power, it keeps down the energy consumption. It is also faster compared to the DRAM, which is cheaper and has greater storage capacity. The modules fall into other classifications.

• Synchronous dynamic RAM (SDRAM) - The conventional DRAM is asynchronous, meaning that it runs independently of the CPU. The synchronous RAM works in harmony with the CPU clock.
• Single data rate synchronous dynamic RAM (SDR SDRAM) - An SDRAM that can only work through a single read or write instruction in a clock cycle.
• Double data rate synchronous dynamic RAM (DDR SDRAM) - An SDRAM that works at twice the rate of the SDR SDRAM. DDR2 SDRAM is a second-generation memory chip that offers better speeds than its predecessor.

What specifications can I look for?

• Speed - Look for the megahertz (MHz) specification to find out how fast the RAM will run on your PC. DDR2 memory can average around 533 MHz. Generally, higher numbers translate to better speeds.
• Latency - It is the time gap that exists between the time when a command gets entered and when it executes. Your aim when looking at this feature is to bring down the latency to a lesser number.
• Device - The memory chip used on a laptop is different from the one found on a desktop PC. For instance, a DDR2 desktop module cannot fit in a laptop that runs on a DDR2 memory chip.
• Capacity - DDR2 memory chips can have anything between 512 MB and 16 GB of storage space. There is a limit to the amount of memory that you can add on your desktop or laptop.
• System - The computer’s motherboard defines the kind of hardware and software that you can install the device. Desktop or laptop’s motherboard may fall into one of two categories, 64-bit or 32-bit systems. The operating systems software places a limit on the capacity of the RAM modules. The 32-bit Windows 7 version puts it at 4 GB.

What if I get confused by the numbers?

It is easy to get it right on the DIMM, MHz, and GB specifications. You might come across other confusing terms like PC2-6400. Basically, PC2 describes the compatible bus system. The numbers that follow refer to the bandwidth or transfer rate. So PC2-6400 is a DDR2 module that peaks at 6400 megabits per second (MB/s).