OMG, the amount of BS spread here gets worse every day.
All three RAM variants perform exactly identical since the exact memory timings live in a boot BLOB that does CPU and DRAM initialization and uses same timings for all Rock 5B out there regardless which LPDDR chips are soldered to which.
The memory controller clocks the DRAM at either 528, 1068, 1560 or 2112 MHz regardless of what the modules are capable of as such 4GB, 8GB and 16GB perform exactly identical wrt to memory as long as same settings are used.
This is an 8GB Rock 5B: http://ix.io/4bMe
This is a 16GB Rock 5B: http://ix.io/4qab
Memory performance identical since both run with
performance DMC governor and the RAM is clocked at 2112 MHz all the time (see tinymembench and ramlat numbers).
If memory performance differs that’s because there’s something called DMC (Rockchip’s Dynamic Memory Interface) and with different settings different boards appear as performing different. You might want to search for ‘dmc’ here in my review.
Ah, ok, you’re just trolling intentionally.