Memory Features

• 2Rx8, generally written as "MRxN", where M and N are powers of 2, is the rank and width of RAM and represents the number of memory chips and their arrangement on the RAM stick. Each chip is a container of data. DDR2, DDR3, and DDR4 RAMs require that each rank has a 64-bit-wide data bus. The rank doesn't affect the speed of RAM, but has a few other effects on the behavior of the memory stick, including (1) Price, since memory sticks with certain rank arrangements are more expensive to produce, and (2) Performance: some ranks cause an increase in latency, negatively affecting RAM performance.
  • 1Rx16: the memory stick has 4 chips on it (64-bit-wide bus/16 = 4), and all these 4 chips are located on 1 side of the stick. This configuration is known for higher latency, so avoiding using such a stick is advised.
  • 2Rx16: 4 chips on both sides (8 chips in total), so this stick has a greater memory capacity (latency is still high.)
  • 1Rx8: 8 chips (64/8 = 8) on one side. Better performance than 1Rx16 and is also cost-effective. 2nd-to-best choice.
  • 2Rx8: 8 chips (64/8 = 8) on both sides of the stick. It can fit more data than 1Rx8. Best choice.
  • 1Rx4: 16 chips (64/4 = 16) on one side. It is more expensive, but has a slightly better performance.
  • 2Rx4: 16 chips (64/4 = 16) on both sides. Can contain as twice much data as 1Rx4, but is expensive.
  • 4Rx4: 16 chips (64/4 = 16) on 2 rows on each side. Can contain as twice much data as 2Rx4, but is expensive.