Also:What is DDR4?
DDR4 is a new memory standard designed to eventually replace DDR3. While it’s true that when running at the JEDEC specified speeds of 2133MHz and 2400MHz DDR4’s higher latencies may produce slightly lower performance clock-for-clock than DDR3, DDR4 is designed to reliably run at much higher speeds that more than offset the increased latency.
In virtually every way, DDR4 is superior to DDR3: it’s capable of being much faster, more efficient, more scalable, and even more reliable. As for cost, much like the transitions to DDR, DDR2, and DDR3, DDR4 will become progressively cheaper as economies of scale take effect.
Physically, a DDR4 module, or DIMM, is very similar to a DDR3 DIMM. DDR4 can use a slightly taller printed circuit board and ups the pin count from DDR2 and DDR3’s 240 pins to 288. The key notch (to ensure the DIMM is not improperly installed) is also in a different place, and the overall shape of the connector has a slight “V” contour to aid installation.
Architecturally, DDR4 is designed to operate at higher speeds and capacities with lower voltage and adds reliability features not present in DDR3.
Why Do We Need DDR4?
When DDR4 is introduced, the initial 2133MHz and 2400MHz speeds will be accompanied by another increase in latency, just as each previous memory technology transition has been. These speeds are essentially the top of the ladder for DDR3, though; while DDR3 kits can be obtained at speeds as high as 3200MHz, ICs capable of performing at those levels are extremely rare. Meanwhile, DDR4 is expected to scale well beyond 3200MHz.
What DDR4 offers is scalability for the future: individual DIMM densities start at 4GB and 8GB and are expected to scale to 16GB in 2015. Bandwidth is also capable of scaling up tremendously. 2666MHz DDR3 isn’t especially common right now; it operates outside of JEDEC spec and requires carefully selected ICs, yet already situations exist that demonstrate a need for increased bandwidth beyond that speed. DDR4 comes out of the gate at 2400MHz, with 2666MHz, 2800MHz, and 3000MHz SKUs already planned.
Read full whitepaper (pdf) (corsair.com)The limitations of capacity in DDR3 are addressed from several angles in the DDR4 specification, with each contributing to an overall massive improvement in potential density.
First, while a DDR3 IC is specified for up to eight internal banks, DDR4 doubles this number to 16 while also organizing them into four addressable bank groups (improving overall performance and efficiency). DDR4 also increases the potential density of the IC itself, all the way up to 16Gb.
Thread: DDR4 Discussion with Corsair (overclock.net)