There’s a dizzying array of DDR RAM and DDR2 RAM out there that it can be hard to upgrade with confidence. With so many types and sub-types it can be difficult to know if you’re purchasing exactly the right thing for your system.
If you wish to upgrade the computer you’re currently using, try our system checker utility – this can provide, with 100% accuracy, the specific RAM modules that are compatible with your computer.
DDR and DDR2 standards:
DDR RAM operates differently than its predecessor, SDRAM. SDRAM sends data only once each clock cycle, a synchronizing wave that regulates the sending and receiving of data. DDR (Double Data Rate) RAM operates by sending data both at the rising and falling of the clock cycle. This doubles the amount of data the RAM can send and provides a significant boost to the memory operation of the computer.
One of the most common types of DDR RAM is DDR400, which operates at 400MHz and can transmit up to 3.2GB/second of data between the memory and the processor. Slightly older computers might use DDR333, which operates at 333MHz and can send up to 2.7GB/s of data. DDR RAM uses a 184-pin socket.
DDR2 RAM is an advancement on DDR RAM. It offers a higher speed between the memory and the system, but operates slightly slower internally compared to DDR memory. While it was initially more expensive then DDR memory with the same performance, DDR2 memory has since come into its own, offering a lower price for faster memory at the same size.
The most common types of DDR2 RAM are DDR2-533 and DDR2-667. The DDR2-533 operates at 533MHz and can transfer 4.2GB/second of data, while the DDR2-667 operates at 667MHz and can transfer 5.3GB/second. However, even faster memory, operating at 800MHz and capable of transferring 6.4GB of data a second is on the market already, with faster versions on the horizon. DDR2 uses a 240-pin socket, which means that DDR and DDR2 memory cannot be used in the same system.
What speed should you get? This is actually less critical than making sure you pick up the right type of memory. While different speeds of memory will usually work together, DDR and DDR2 memory are physically incompatible and cannot fit into the same sockets.
When mixing RAM speeds it is important to note that the faster RAM slows down to operate at the same speed as the slower RAM in the system. If you’re running slower RAM and plan to upgrade by simply adding more RAM modules as opposed to replacing them, you won’t be getting all you could out of your new ram. Keep in mind that OEMPCWorld.com will buy back your old ram. If you’re unsure what type of RAM your system uses, don’t worry, there’s an easy way to find out. A the top of this page click on the ‘Check Your System’ button if you’re using the computer you plan to upgrade, and it will report back to you what type of memory that computer uses. Or, if you know the model of the computer you want to upgrade, enter it into the model number field and we’ll return the correct type of RAM to use in your system. Otherwise, feel free to browse our website and take a look at all the types
of RAM we offer.
At OEMPCWorld.com we buy back your old DDR RAM!