How to Buy Computer Memory?

Answer 1

What do all these memory specifications mean?

Pins: These are the connectors that transfer data between the memory chip and the motherboard. Desktop memory chips come in 168. 184, or 240-pin while laptop memory comes in 140, 200, or 204-pin formats. The number of pins must match the slots on your computer’s motherboard.

DDR: This stands for Double Data Rate. Motherboards with DDR support can access two or more memory chips at the same time. DDR2 can access two chips at the same time while DDR3 can access three chips. This means if optimum performance you should always have pairs of DDR2 memory chips or triplets of DDR3 memory chips.

You will see DDR on the pin description because different types of DDR memory have the pins spaced differently: This means a 240-pin DDR2 memory chip won’t fit in a 240-pin DDR3 slot. DDR is also used when referring to speed.

Speed: This is listed by either DDR or PC standard. DDR is quoted by its speed in megahertz, so a DDR2 533 memory chip runs at 533Mhz. The PC standard lists the number of megabytes a chip can read or write in one second. Theoretically a DDR2 533 chip can transfer 4,200 megabytes of data per second so it would be listed as PC2-4200.

Latency: This is how long it take the memory chip to access RAM once it has received a command from the processor. This is quoted as four numbers, for example %EF%BB%BF2.5-3-3-7. The most The first number, Column Access Strobe (CAS,) is the most important. The lower these numbers are, the faster access the RAM will be. However, this difference is slight compared to overall speed.

What type of RAM do I need for my computer?

Major memory manufacturers will also have tools on their sites to match your computer’s model with compatible RAM. You must use the same number of pins and the same DDR type, but any speed can be used. If there is more than one speed of RAM in a computer all of the chips will run at the slowest chip’s maximum speed. Why would you do this? Often the exact type of RAM in an older computer will either not be available or it will come with a high price tag.