If you had asked me last year if DDR4 RAM had a chance of reaching 7 GHz speeds before DDR5 entered the mainstream market, I would have said probably not. At the time, overclockers and memory manufacturers were in a protracted race to reach 6 GHz; G.Skill won that race in September and now, eight months later, owns the new memory frequency record with DDR4-6666. I would be surprised if it doesn't reach 7 GHz by the end of the year. [This record was achieved on an Asus ROG Maximus XII Apex motherboard paired with a 10th generation Core i9 10900K processor.

G.Skill stated in the press release that it worked closely with the Asus ROG team to achieve the record, as acknowledged by HWBot. The announcement came a day after G.Skill revealed that it is preparing new high-speed memory kits up to DDR4-5000 for Z490 motherboards. These products can be purchased without overclocking expertise.

It is doubtful that we will see DDR4-6666 memory kits for sale, as G.Skill suggests that they used liquid nitrogen to achieve that speed (LN2 is definitely used for the CPU, and one would imagine the same for RAM). The only DDR4-5000 kit on the market is Corsair's 16GB kit, priced at about $1000; if DDR4-6666 memory kits exist, their prices would be even more outrageous.

Nevertheless, it is nice to see G.Skill involved in the overclocking scene, even if this kind of record is not feasible in today's everyday use. Meanwhile, mass production of DDR5 RAM will likely begin in 2021.