Samsung have introduced their first 8Gb(gigabit) LPDDR4, which simply means low power double data rate 4 type of mobile DRAM. This chip is built on a very large DRAM component with 20nm process, which provides something like how Intel’s Bay Trail is known for, a chip which could provide high level performance with minimum power usage. The transfer rate of the LPDDR4 chip is 3,200 megabits per second(Mbps) which means double the capability of the elder sibling LPDDR3 DRAM which also based on 20nm process.
How would this turn into 4GB RAM? If four of these 8GB chips gets combined into a single component, it would provide the best ever performance of its mobile category. Samsung also claims that their new LPDDR4 would consume 40 percent of less energy and 50 percent of higher performance than the LPDDR3.
The reason I reckon that the next upcoming Note series from Samsung, the Galaxy Note 4 would feature a 4GB of RAM is because most of their note series tend to feature the latest and most noticeable upgrade compared to the S Series from Samsung like how Galaxy Note 2 got its 2GB RAM, and Galaxy Note 3 got its 3GB RAM, simultaneously this happened to the Samsung Galaxy S4 and the upcoming Samsung Galaxy S5 would feature 3GB of RAM. 
For those who have not upgraded their smartphone to the Samsung Galaxy Note 3, are you still intending to get it, or wait till about Q3, or Q4 of next year until the Samsung Galaxy Note 4 comes out? Well, I have already purchased the Note 3, so I would just wait patiently till the next big thing arrives.