RAM

Updated: 2020-10-16

DDR = Double data rate

DDR5 vs DDR4

DDR5 is expected to be published in 2020.

  • reduced power consumption: DDR5 1.1V, DDR4 1.2V
  • DDR4: frequency between 800 and 1600 MHz (DDR4-1600 through DDR4-3200)

DDR vs GDDR

  • G is for graphics and GDDR is for GPU; DDR is on the motherboard and is for CPU.
  • GDDR is designed for use by RISC (Reduced Instruction Set Computers) machines and DDR by CISC (Complex Instruction Set Computers). RISC machines perform one operation per tick, CISC machines perform multiple operations per tick. GDDR is very fast at dealing with the “one tick, one operation” workloads. DDR is very fast at dealing with “one tick, multiple operation” workloads
  • GDDR is built for much higher bandwidth, with a wider memory bus.
  • GDDR has lower power and heat dispersal requirements compared to DDR, allowing for higher performance modules, with simpler cooling systems.
  • GDDR can request and receive data on the same clock cycle, where DDR cannot.
  • GDDR being optimized for bandwidth while DDR is optimized for latency

DDR vs LPDDR

LP = Low-Power.

  • LPDDR consumes less power and is targeted for mobile devices like smartphones, tablets
  • DDR has a 64-bit wide memory bus, LPDDR also permits 16- or 32-bit wide channels

Optane

Optane memory could replace DDR DRAM, retains data even if a computer is shut off