MSI Big Bang XPower Motherboard

Memory Support

Socket LGA1366 CPUs, like socket LGA1156 and AMD processors, have an embedded memory controller. All other Intel CPUs use an external memory controller, which is located on the north bridge chip (a.k.a. MCH or Memory Controller Hub) from the chipset. This means that with other Intel CPUs the chipset (and thus the motherboard) is the component that says what memory technologies and the maximum amount of memory you can have on your PC.

Since now the memory controller is inside the CPU, it is the processor, and not the chipset, that defines the memory technologies and the maximum amount of memory you can have. The motherboard, however, may have a limitation as to how much memory can be installed.

The Core i7 integrated memory controller accepts only DDR3 memory (up to 1.65 V; memories that require more than that won’t work and may even damage the CPU) and supports the new triple-channel memory architecture. Even though Core i7 CPUs officially only support up to DDR3-1066, MSI Big Bang XPower supports memories up to DDR3-2133 through overclocking.

The triple-channel architecture allows the CPU to access three memory modules at the same time to store or retrieve data, increasing the number of bits that are transferred per clock cycle from 128 (on dual-channel architecture) to 192. Thus this makes a 50% improvement on the maximum theoretical memory bandwidth compared to dual-channel architecture, if both are running at the same clock rate. For example, DDR3-1333 memories running on dual-channel have a maximum theoretical transfer rate of 21 GB/s while on triple-channel they have a maximum theoretical transfer rate of 32 GB/s.

Another highlight of Big Bang XPower is the presence of six memory sockets and not only four, like Intel DX58SO “Smackover”, for example. This allows you to make future memory upgrades without having to remove your current memory modules and, at the same time, to keep the maximum performance possible.

Just to clarify, in order to achieve the maximum performance you have to install three or six memory modules. If you install three memory modules you have to use sockets with the same color (on Big Bang XPower three sockets are black and three are blue). If you install a different number of memory modules the system won’t achieve its maximum possible performance.

On motherboards with only four memory sockets you have a problem: if you add a fourth memory module this module will be accessed at single-channel performance (1/3 of the maximum transfer rate) so for you to add more memory keeping the maximum performance you have to remove your old three modules and install new ones. This upgrade is more expensive than using a motherboard with six sockets, where you can simply add three more modules and keep your old modules installed.

According to MSI you can have up to 24 GB with this motherboard.

Figure 3: Memory modules. Install three or six modules for the best performance.