Ryzen is the first competitive line of desktop processors by AMD in a decade. Our comprehensive review of the top-dog Ryzen 7 1800X concluded that the chip competes with Intel's premium Core i7-7700K processor in a wide range of tests and restores competition in the market. We also remarked on the Ryzen platform's modern I/O standards, such as dual-channel DDR4 system memory support and PCI-Express gen 3.0 x16 slots.
AMD Ryzen processors come with a dual-channel (128-bit wide) DDR4 memory interface driven by an integrated memory controller (IMC). The processor's rated baseline memory clock is DDR4-2666, although the IMC supports a wide range of memory dividers, beginning with 1866 MHz, 2133 MHz (JEDEC baseline), 2400 MHz, DDR4-2666, 2933 MHz, and 3200 MHz. These are all JEDEC-prescribed speeds, and the Ryzen platform does not support Intel XMP technology, which lets you run a high-rated memory kit at its advertised speeds with one click in the BIOS. Some motherboard vendors are trying to innovate features into their UEFI setup programs that translate XMP profiles of the memory modules into presets that can be enabled on the Ryzen platform (while ignoring settings such as NB clock).
The enthusiast memory market is vast. You get single-module, dual-channel, and quad-channel kits with combinations of 4 GB, 8 GB, and 16 GB modules, in a variety of memory speeds that are enabled through XMP profiles. A DDR4-4000 memory kit could easily cost double that of a DDR4-2133 kit. Add to that the ongoing
short supply in the DRAM industry that has caused tremendous escalations in memory costs and this is where we find it important to test whether you really need to invest in faster memory to make the most out of your Ryzen build, or if you're fine buying the cheapest 2133 MHz kit there is.
We got our hands on a G.Skill Flare X series 2x 8 GB dual-channel memory kit and ran it on a machine with an Aorus AX370-Gaming 5 motherboard and a top-tier Ryzen 7 1800X eight-core processor. The memory was run at DDR4-2133 (JEDEC baseline), DDR4-2400, DDR4-2666 (Ryzen default), DDR4-2933, and DDR4-3200. The DDR4-3200 data point was further spread across three CAS latency settings, 14T, 16T, and 18T. All other settings were run at tight 14T CAS latencies. The test bed was put through a wide selection of CPU-specific and gaming tests.