How to Get More Out of Memory
The way to get every last bit of performance out of your computer is to make sure the CPU gets the data it needs in a timely fashion. That's what RAM is good for, the more and faster your RAM, the easier it is to keep the processor fed.
What is DDR?
DDR is an evolution from the earlier SDRAM standard, which introduced the concept of synchronizing the memory clock to its interface bus, making it easier for each memory module to communicate with the chipset and the rest of the computer. Each DIMM used a 64-bit interface and carried one bit of data for every tick of the clock. Unfortunately, once bus speeds started reaching 100 MHz it grew harder and harder to increase the clock rate of the interface. DDR was an attempt to sidestep that problem and offered a number of advantages compared to its predecessor as the following comparison shows:
- SDRAM: Running at speeds from 66 to 133 MHz, SDRAM comes in a 168-pin package that requires 3.3 Volts for signaling.
- DDR: Running at speeds from 200 to 400 MHz, DDR comes in a 184-pin package that requires 2.5 Volts for signaling.
How to Select RAM
Choosing RAM involves making a number of decisions, most of which are initially going to be based on compatibility. A Samsung DDR-400 1 GB Module can provide quite a bit of bandwidth, but you need to be sure it will work in your system before you try to install it. There are several different factors to consider:
- CAS Latency: Latency is the delay between sending a request and the data being available. When possible, you want at least CL3 DDR-400 if not faster memory.
- Data Protection: While most DDR-400 is unbuffered, servers can often benefit from ECC PC3200 DIMM memory which provides robust protection for mission-critical data.
Using Memory
It's always a good idea to have as much RAM as your motherboard and processor can handle. One thing you should check is both the total amount of memory the system can handle as well as the size and number of DIMMs. For example, one computer may be able to handle 4 GB DDR memory but only in four 1 GB DIMMs; another may require two Samsung 2 GB DIMMs for the same capacity. It all comes down to the timings and how the system is set up. Not all motherboards can run at full speed with every memory slot filled. Still, the more RAM you have, the easier it is to switch from one program to another as the computer does not have to load everything from the hard drive.