Real-world tests
Faster memory makes more sense when it acts as the framebuffer for the integrated graphics.
The first two synthetic benchmarks show that it's worthwhile to invest in even-faster DDR3-2,133 memory. Performance goes up by a further five per cent.
The faster 2,133MHz-rated memory doesn't now command much of a price premium over 1,866MHz RAM, and we'd go with it every time on an AMD FM2 build. Kingston's 8GB sticks continue to produce middle-of-the-road performance.