Quad channel RAM kits offer wider bandwidth on motherboards that support it, which results in faster transferring speed. If you motherboard only support dual-channel RAM, then getting quad-channel kit won't get you any increase in bandwidth over dual-channel.
O que isto basicamente significa que virtualmente não há diferença entre a memória dual-channel e os kits de memória quad-channel. O que faz a diferença é o que os modos de canal de memória suportados pela placa-mãe. A maioria das placas-mãe de Canal Quádruplo suporta Quad, Dual e Single, dependendo de quantos módulos estão instalados em qual slot.
Canal quádruplo:
The architecture can only be used when all four, or a multiple of four, memory modules are identical in capacity and speed, and are placed in quad-channel slots. When two memory modules are installed, the architecture will operate in dual-channel architecture mode. When three memory modules are installed, the architecture will operate in triple-channel architecture mode.
Triple Channel:
When operating in triple-channel mode, memory latency is reduced due to interleaving, meaning that each module is accessed sequentially for smaller bits of data rather than completely filling up one module before accessing the next one. Data is spread amongst the modules in an alternating pattern, potentially tripling available memory bandwidth for the same amount of data, as opposed to storing it all on one module.
The architecture can only be used when all three, or a multiple of three, memory modules are identical in capacity and speed, and are placed in three-channel slots. When two memory modules are installed, the architecture will operate in dual-channel architecture mode.
Canal duplo
Dual-channel-enabled memory controllers in a PC system architecture utilize two 64-bit data channels. Dual channel should not be confused with double data rate (DDR), in which data exchange happens twice per DRAM clock. The two technologies are independent of each other and many motherboards use both, by using DDR memory in a dual-channel configuration.
Para responder à sua pergunta específica:
For example, does this counts as a quad channel or dual-dual channel?
2x8GB 10-10-10-30 1600 + 2x4GB 9-9-9-24 1866
Você teria que ativar o modo Quadruple-Channel dentro de seu BIOS / UEFI.
Específico para a sua placa-mãe :
You have to install identical DDR3 DIMM in DDR3_A1, DDR3_B1, DDR3_D1 and DDR3_C1 (Black slots; see p.11 No.2 and No. 5), so that Quad Channel Memory Technology can be activated
If only two memory modules are installed in the DDR3 DIMM slots, then Dual Channel Memory Technology is activated. If three memory modules are installed, then Triple Channel Memory Technology is activated. If four memory modules are installed in the DDR3 DIMM slots, then Quad Channel Memory Technology is activated.
Como seus módulos de memória não são idênticos, talvez você não consiga ativar a tecnologia de memória de quatro canais.