RAM memory is a very important aspect to take care of when buying a new PC, since nowadays almost all PCs can use a technique called “dual channel”, which doubles the RAM memory performance.

In order to make this technique work, the motherboard has to support it and you also have to install RAM memory using two separated modules. For example, if you are buying a PC with 512 MB RAM, the ideal scenario is to buy two 256 MB modules. These two modules must be installed in separated memory channels. This is normally accomplished by jumping one memory socket: if you install the first memory module on the first memory socket on the motherboard, the second module must be installed on the third socket (and not on the second one).

So, when buying a new PC you have to check if your RAM memory was installed like this.

Nowadays all new computers based on Pentium 4, Celeron D, Pentium D, Athlon 64 (socket 939), Athlon 64 FX and Athlon 64 X2 support this technology.

Computers based on socket 754 (socket 754 Sempron and socket 754 Athlon 64 CPUs) don’t support dual channel mode. Socket 462 computers (socket 462 Sempron and Athlon XP CPUs) can support it or not, it will depend on the motherboard (you will need to use a motherboard based on nForce 2 Ultra or VIA KT880 chipsets in order to use this feature).

There are two ways to know if your PC is using or not DDR dual channel without opening it. One is paying attention to POST, which is what text-based screen that shows up just after turning your PC on. Usually when the RAM memory is installed on dual channel configuration something telling this condition will show up, like “Dual Channel Enabled” or something similar (see Figure 3). The PC portrayed on Figure 3 is with DDR dual channel scheme correctly enabled.

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Figure 3: Checking the number of memory channels used on POST.

The second way of checking whether DDR dual channel is enabled or not is thru software. Everest is a very good choice for this. On it, go to Motherboard, Motherboard and check what is below “Memory bus properties”. “Bus width” item can be listed as “64-bit”, meaning that your PC is configured to use just one memory channel, or “128-bit”, meaning that your PC is correctly configured to use two memory channels. On Figure 4 you can see a PC using just one memory channel and, on Figure 5, a PC using two memory channels (DDR dual channel).

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Figure 4: This PC is using just one memory channel.

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Figure 5: This PC is correctly using two memory channels.

For more information on this subject, read our tutorial Everything You Need to Know about DDR Dual Channel.