RD:
Happy New Year.
I'm glad that the misunderstanding has been cleared up.
My system only runs at 333MH which only requires PC2700 (333MH) but my motherboard is rated at 400MH. I am successfully using PC3200 (400MH). I figured that I could always use the faster memory in the future if I ever upgrade or purchase a new system.
Yes, if your system can handle the faster memory, you will get better results by using the faster memory boards in all three slots. However, I doubt if after spending another $65 you will notice a big difference.
Here is a table from the Crucial website:
Memory Speeds
Technology Speed Module Bandwidth
(max theoretical)
SDR PC100 0.8 GB/sec
SDR PC133 1.0 GB/sec
DDR PC1600 1.0 GB/sec
DDR PC2100 2.1 GB/sec
DDR PC2700 2.7 GB/sec
DDR PC3200 3.2 GB/sec
DDR PC4000 4.0GB/sec
DDR2 PC2-3200 3.2GB/sec
DDR2 PC2-4200 4.2GB/sec
DDR2 PC2-5300 5.3GB/sec
DDR2 PC2-6400 6.4GB/sec
The higher the number, the faster the memory; for example, PC133 is faster than PC100, and DDR is faster than SDR.
Remember, it's best to match the memory that is currently in your system.
It might seem confusing, but faster memory will NOT necessarily make your system faster. Your computer will run only as fast as the "slowest link" in your system, so you can't speed up your computer by adding faster memory. The way to make your system faster is to add more megabytes (MB) of memory.
Do I need error checking?
Most desktop computers take what's called "non-parity" memory and do not need error correction code (ECC), or "parity" modules. (However, in most cases ECC modules will work in desktops.) ECC modules look for errors in data and are most often found in servers and other mission-critical applications used by large networks and businesses. There are, however, a few desktop systems that do use ECC modules. In any case, you should buy the type of memory that's already installed in your system. You can tell which kind you have by looking at one of the modules currently installed. Count the RAM chips on one module. If the number of chips can be evenly divided by three or five, you should buy ECC or parity (whichever is offered for your system). If not, you should buy non-parity. For example, if one of your modules has nine RAM chips, you should buy ECC or parity. If one of your modules has eight RAM chips, you should buy non-parity. Or, you can look up your system in the Memory Advisor tool.
If you're building your own system, we recommend using non-parity parts unless you will be using your system as a server or have a need for error checking. ECC and parity parts are slower than non-parity parts.
What does "CL" stand for?
CL stands for CAS (column address strobe) latency, which is the number of clock cycles it takes before data starts to flow after a command is received. Low CAS latency at a given frequency is faster than high CAS latency at that same frequency. (For example, CAS2 is faster than CAS3.) However, lower CAS latency will NOT necessarily make your system faster. Your computer will only run as fast as the "slowest link" in your system, so you can't speed up your computer by adding memory that is faster than your current memory. The way to make your system faster is to add more megabytes (MB) of memory.
In general, we recommend using parts with the fastest speeds. This will give you the highest level of compatibility and future upgrade path.
If you don't know the CAS latency of the memory you currently have installed, don't worry; any of the modules listed in the Memory Advisor tool are guaranteed to work in your system.
Here is a paragraph from the Crucial website that may help you.
Common types of memory technology today include DDR2 (double data rate, second generation) SDRAM and DDR (double data rate, first generation) SDRAM. Many older systems use SDR (single data rate) SDRAM, fast page mode (FPM), or extended data out (EDO). Each of these memory types comes in a variety of speeds. And while most systems will accept only one type of memory technology (the very few motherboards that can accept more than one type of memory will only allow you to use one type at a time), it's okay to mix the speed of the memory in a system. Just keep in mind that your computer is made to handle a specific memory speed, so even if you add a faster speed memory, your computer will only allow it to run at the speed your computer was made to handle.
