Differences between the 2 types of RAM.
In the Surface Book teardown, under the step 16, there is a Samsung K4E4E324EE 4 Gb (512 MB) DRAM.
Under step 17, there is a Samsung K4E6E304EE-EGCF 16 Gb LPDDR3 1867 MHz SDRAM (4 chips for a total of 8 GB).
The stated RAM for the Surface Book in the teardown is 8 GB.
What is the 4GB ram used for, if it is not included in the total RAM ?
Is this a good question?