When AMD implied several weeks ago that its next-generation Ryzen 7000-series 'Raphael' processors would have remarkable DDR5 overclocking capabilities, it didn't really elaborate on the capabilities. But as it turns out, Raphael will support DDR5-5200 memory out-of-box, according to Apacer, a leading supplier of memory modules.
Apacer recently published a table (discovered by @momomo_us) describing which types of memory are supported by modern and upcoming processors from AMD and Intel. Intel's Alder Lake and Sapphire Rapids CPUs support DDR5-4800 memory, just like AMD's Ryzen 6000 'Rembrandt' APUs. Meanwhile, AMD's Ryzen 7000 'Raphael' and EPYC 7004 'Genoa' processors based on the Zen 4 microarchitecture are said to support faster DDR5-5200 SDRAM.
DDR5-5200 memory modules will provide about 8.3% higher peak memory bandwidth than DDR5-4800 DRAM sticks currently officially supported by Intel's Alder Lake processors, so AMD's next-generation desktop CPUs will have a slightly more advanced memory subsystem when compared to Intel's existing processors. Meanwhile, since DDR5-5200 is within JEDEC's specifications for DDR5, it is logical to expect Intel to support this speed in the future as well (after all, Apacer's table says nothing about memory subsystem of Intel's Raptor Lake processors).
While Intel's existing 12th Generation Core 'Alder Lake' CPU officially support DDR5-4800 memory, as long as they are properly cooled, they can handle memory data transfer rates 8,000 MT/s or higher. To that end, it is reasonable to expect AMD's next-generation Ryzen 'Raphael' CPUs to be at least as capable as Intel's Alder Lake chips, so their DDR5 overclocking capabilities should be considerably more impressive than out-of-box DDR5 support.
DDR5 was designed to provide significant performance and capacity upgrades when compared to DDR4 memory, so over time DDR5 memory chips will further gain both performance and capacity. Right now high-speed DDR5 modules are quite expensive and It remains to be seen whether high speed memory modules gain significant popularity with next generation processors.