There are four major reasons why DDR4 is set to replace DDR3: it's capable of hitting faster speeds, it's capable of hitting higher densities (16GB DIMMs are expected in 2015), it has improved error correction built into the baseline specification, and it consumes less power for equivalent or better performance than DDR3. In short, while DDR3 is butting up against its limitations today, DDR4 still has a tremendous amount of room to scale.

Yes! We have been working hard with all major motherboard vendors to ensure compatibility with our high speed DDR4 memory, and that includes XMP. DDR4 employs a new specification, XMP 2.0, while DDR3 remains on XMP 1.3.

Very similarly to DDR3, but with some caveats. For starters, Haswell-E tops out at a 2666MHz memory strap, which is very low for what DDR4 can do. Since XMP specifies speeds in excess of 2666MHz, your motherboard BIOS has to compensate somehow. Typically, when XMP tells the motherboard to use a higher memory speed than 2666MHz, the motherboard BIOS will bump the BClk strap from 100MHz to 125MHz. That's normal, but that change will also increase the clock speed of the CPU itself; a well-designed BIOS will compensate and bring the CPU clock speed in line.

While we've been working around the clock with motherboard vendors to maximize compatibility and performance, these technologies are all very new. If you have trouble with stability using either XMP profile, we recommend either manually entering the speed and timings the DDR4 is rated for or running your memory at its default speeds until your motherboard vendor provides a BIOS update to improve stability.

We're launching DDR4 at up to 3000MHz speeds and 8GB per stick densities, but that's just this year alone. DDR4 is expected to hit 16GB densities in 2015, allowing your X99 motherboard to support a staggering 128GB of memory (provided it has eight memory slots). In short, it's gonna get bigger, and it's gonna get faster.