A. Single or dual or quad channel memory access doesn’t have anything to do with the individual RAM modules — an individual RAM DIMM is the same whether it is sold alone, or in a package of 2 or 4 matching pieces as a kit.
The key to dual or quad channel memory access is
1) the motherboard and memory controller on the CPU have to support it, and
2) you have to install 2 or 4 pieces of RAM that match identically – in terms of size, speed and configuration – into the appropriate slots on the motherboard (refer to the manual for instructions of slot population order).
Not many desktop machines support quad channel access, but most modern desktop and notebook machines support dual channel access. Dual channel access improves the speed that the CPU can access the memory locations on the modules by treating two modules as one big module. Although the theoretical bandwidth is doubled, the effective real world difference is around 6% performance improvement in memory intensive use.
If you buy an appropriate specification quad channel kit (that is, four pieces of matching RAM), you can certainly install them in a computer that supports dual channel, and you will get dual channel access.
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