Therefore, the effective prefetch for DDR4 is wider than DDR3. This is done by using a multiplexer to time division multiplex its internal banks. The two bank groups are separate and can execute two independent 8n prefetches.
As you can see above, DDR3 has an 8n prefetch with four memory arrays forming a bank group connected via a multiplexer to the I/O controller.Īlthough DDR4 maintains the same 8n prefetch and burst length as DDR3, it has two memory bank groups per channel. However, there is one key difference in the memory bank groups of DDR3 and DDR4 memory. Both DDR3, as well as DDR4, has a burst length of 8 and an 8n prefetch. Unlike the transition from DDR2 to DDR3, the move to DDR4 didn’t increase the burst length or prefetch. While running at 1200 to 1600MHz, DDR4 operates at a voltage of 1.2v, while DDR3 had a voltage of 1.5v, all the while running between 4MHz. DDR4 vs DDR3Īside from the obvious (faster frequencies and lower latency), the primary advantages of DDR4 memory over DDR3 are higher DIMM sizes (up to 64 GB, DDR3 is limited to 16GB) and a considerably lower operating voltage. DDR4 memory modules capable of running at 1800MHz (or 3600MT/s) out of the box are now widely available while some can even be pushed to as high as 5000MT/s. With the coming of AMD’s Ryzen processors and the MCM design, high-speed DDR4 memory has suddenly become more relevant.
Released in 2014, it initially focused on reducing the voltage and power consumption rather than increasing the operating frequencies. In DDR4 memory, two transfers occur per cycle (Double Data Rate) which is why the effective data rate is twice the frequency: 3600MT/s for 1800MHz and 3200MT/s for 1600MHz.ĭDR4 is the latest iteration of DRAM. This isn’t the operating frequency but the number of MT/s (million transfers per sec).
OEMs often advertise DDR4 speeds as DDR4-3200 or DDR4-3600. In this post, we compare DDR3 vs DDR4 vs DDR5 and analyze the difference between the last three generations of DRAM.ĭDR4 runs between 1200 to 1600MHz. It’s successor, DDR5 has been specified, but it’s yet to hit the market. The latest iteration of DRAM is DDR4 memory. It‘s slower than static ram (SRAM) but is much more affordable which is the primary reason for its widespread use. Nearly all kinds of volatile memory is based on dynamic random access memory or DRAM.