If you buy a new computer today, it may well be using DDR5 memory. As the name suggests, this represents the fifth generation of the DDR (double data-rate) RAM standard, originally laid down in the year 2000. Of course, if you want to delve into the history of memory you can go much further back than that – the Joint Electron Device Engineering Council (JEDEC) has been developing standards for electronic storage since 1944.
For now, though, let’s focus on how DDR5 builds on its predecessor. DDR4 is a versatile standard that officially comes in seven flavours, dubbed DDR4-1600, 1866, 2133, 2400, 2666, 2933 and 3200. You might assume that the numbers indicate the speed at which the different variants run, and that’s basically right, although since DDR transfers data at twice the speed of the internal clock, a DDR-1600 module actually runs at 800MHz, and so forth.
Take a look at DDR5 options and you’ll see that they start at DDR5-4800 and go all the way up to DDR5-7200. That’s an enormous increase, with the top frequencies more than doubling – but that doesn’t necessarily mean that DDR5 RAM will run twice as quickly.
THE SECRET OF LATENCY
The chips in a RAM module are fast, but they’re not capable of reading or writing a full 64-bit chunk of data every clock cycle. If you look at the specifications of modern
