DRAM Will Run Faster With All Slots Filled
Running two sticks of DRAM puts less stress on the memory controller than four. Less electricity is needed, the memory controller needs less voltage to remain stable and, while it isn’t noticeable, the DRAM runs ever so slightly quicker (generally). The same holds true for tri- and quad-channel motherboards. Part of the misconception is that four DIMMs (often sold as a quad-channel set) will always run in full quad-channel mode, even though a dual-channel motherboard doesn’t support this feature.
Dual-Channel Mode Doubles The Data Rate, Or Is Twice As Fast
This is another misconception. The DRAM itself is DDR (double data rate), so it runs at double the clock frequency (800MHz DRAM has a 1600 MT/s data rate). When you put two DIMMs in dual-channel mode, the DRAM goes from operating as an individual 64-bit device to working together and being seen by the MC as a single 128-bit device. Theoretically, that would double the bandwidth, but in actuality, it provides a performance boost of only 20 to 50 percent on Intel CPUs, and a little less on AMD rigs.
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