Types of RAM

There are many different types of RAM out there, and finding the type for your computer can be a little confusing. Fortunately, while you hear about many different types of RAM, there is usually one prevailing type that most computers take. But if you’d like to be a RAM expert (and who doesn’t?) read on to learn about the many different types of Random Access Memory.

  • DRAM – this is the main type of RAM that you buy when you want to increase your computer’s memory. It comes in two times: SIMM and DIMM. SIMMs used to be the main form of memory, while DIMMs are the norm now. Both are very similar except that SIMMs only had a 32-bit path while DIMMs have a 64-bit path. Most processors, including Pentiums, use a 64-bit bus. What does any of that mean? Basically, if your computer uses SIMMs, you have to buy and install them in matched pairs so your processor can use them simultaneously (the two 32-bit SIMMs are seen as one 64-bit piece of memory). DIMMs, on the other hand, can be installed singularly, so you don’t have to worry about buying your RAM in pairs.
  • SRAM – this type of RAM is generally not something you’ll need to buy. It’s used in CPU caches, buffers for hard drives and CD/DVD burners, and printers. In fact, when you print something, your document or image is sent to your printer’s SRAM first and is then printed from there.
  • EPROM (Erasable Programmable Read Only Memory) and EEPROM (Electrically Erasable Programmable Read Only Memory) RAM are different from SRAM and DRAM in that when power is turned off, the EPROM and EEPROM don’t lose the information stored in them. Today, EPROM and EEPROM are being replaced by Flash Memory, and you will probably never need to purchase them for your computer.
  • Flash Memory is similar to EEPROM in that the data on it can be erased and replaced by other data. If you’ve ever bought a memory card for a digital camera or a USB drive to store data on, you’ve bought Flash Memory. Flash Memory does not lose the data saved on it when power is turned off, and it’s very, very easy to save new data to it or over-write the data on it. While technically Flash Memory is a type of EEPROM, the term EEPROM is usually only used when discussing non-Flash EEPROM that is erasable in bytes.

26.06.2008. 09:40