While the competition between Intel and AMD is going on in the server CPUs territory, with Xeon and EPYC lineups, Intel has revealed its roadmap for the future Xeon CPUs. The roadmap includes the confident plans until 2024; then it goes on as “Future Gen”. According to the roadmap, Intel is planning to release a new fork for the Xeon line up as E-Core series.
Power efficiency-focused server CPUs
Sapphire Rapids will be the first Xeons we will meet, they will be released this year with Intel 7 process, simply 10 nanometers. Next year Emerald Rapids will be released using the same manufacturing process. By the year 2024, things will be getting more interesting. Granite Rapids will be the successor of Emerald Rapids and it will use the Intel 3 process, which will be equivalent to 3 nanometers manufacturing technology. And the Xeon lineup will be forked into the P-Core series and E-Core series with the addition of Sierra Forest CPUs.
Sierra Forest CPUs will be the first CPUs to present the E-Core series of Intel. According to Intel, the new E-Core series will be delivering higher power efficiency and core density compared to the P-Core series. Those will be more suitable for latency-tolerant parallel workloads, the company says. In addition, multiple E-Cores will be able to fit into the physical space of one single P-Core.
Core density might reach 4x
Intel will probably deliver a server-focused CPU that is filled with full E-Cores. The 12th gen consumer-focused CPUs have some E-Cores and some P-Cores inside them. E-Cores are smaller, power-efficient, but also have lower performance than the P-Cores. You can see the picture below how it looks in current-generation consumer-grade CPUs.

On the mid-left side, there are two clusters of 4 E-Cores, taking up very little space. On the mid-right side, you can see the big P-Cores taking up much more space. The space requirement looks like approximately 1 to 4; so we can expect Xeon E-Core CPUs completely filled with E-Cores to have 4x core density compared to its P-Core equivalent.