Apple's new iPhone 5S and iPad Air both use 1GB LPDDR3 SDRAM from Elpida. With Apple being the first to introduce a 64bit processor this year, we're likely to see Apple shift to the upcoming LPDDR4 standard in the fall of 2014. It will allow Apple to advance their Retina Display quality to the next level.
LPDDR4 is the next-generation high-speed and low-power mobile DRAM standard that was just announced by Samsung and SK Hynix. The 8Gb LPDDR4 DRAM, which the two companies disclosed, is a product, which the 20-nano microfabrication technology is applied to. It implemented 3200Mbps data transmission speed, twice faster than that of the existing LPDDR3.The operating voltage is 1.1V, 0.1V lower than that of LPDDR3.
Both companies have released LPDDR4 now even before LPDDR3 became a mainstream product in the DRAM market because the performance of application processors (AP) and displays was enhanced so fast.
Apple embarked on the performance competition first by applying the 64bit AP to the iPhone 5S. Samsung Electronics also decided to apply the 64bit AP to its new smartphones in 2014. High-resolution displays are also adopted for smartphones and tablet PCs. The resolution of mobile displays is expected to increase from WQXGA (2560×1600) to UHD (4096×2160) in 2014
With the advancement of Apple's A7 to 64bit and with yet higher resolution displays on the way, the DRAM performance must also be improved in proportion. What matters is power consumption. The existing LPDDR2 or LPDDR3 DRAM cannot withstand the power consumption necessary for high-performance APs and displays. That's why the low-power interface-based LPDDR4 DRAM is needed. If the LPDDR4 DRAM is adopted, the DRAM capacity can be increased by 40% for the same power consumption.
Samsung Electronics is planning to release LPDDR4 DRAM in time for the release of UHD smartphones, tablet PCs and ultra-thin notebook PCs that are more than 4 times clearer than full HD.
Whether Apple will be remain with Elpida or switch to another supplier for LPDDR4 DRAM is unknown at this time. While SK Hynix is awaiting industry approval for their LPDDR4, Samsung's spokesman Benjamin Lee confirms that their product has been approved.