http://www.apple.club.tw/ipad-air-2%E7%A2%BA%E5%AF%A6%E6%98%AFa8x-2gb-ram/
So this would be the A8X to be (presumable) released this Thursday.
There are two ELPIDA dram chips next to the A8x and with some
imagination we might read the (very blurry) part number right below
the ELPIDA logo as "FA164A..." which would make them 16Gb LPDDR3
parts each with a 2x32 bit databus.
That would make a decent 4GB dram in total with a wide 128 bit bus.
If I'm reading the "GD-F" on the 3rd line correctly then that should make
them DDR3-1600 parts giving the A8X a desktop like bandwidth of
25.6 GB/s.
Well, I guess Thursday, 16th we'll find out the details with the introduction
of the new iPads.

So this would be the A8X to be (presumable) released this Thursday.
There are two ELPIDA dram chips next to the A8x and with some
imagination we might read the (very blurry) part number right below
the ELPIDA logo as "FA164A..." which would make them 16Gb LPDDR3
parts each with a 2x32 bit databus.
That would make a decent 4GB dram in total with a wide 128 bit bus.
If I'm reading the "GD-F" on the 3rd line correctly then that should make
them DDR3-1600 parts giving the A8X a desktop like bandwidth of
25.6 GB/s.
Well, I guess Thursday, 16th we'll find out the details with the introduction
of the new iPads.