In the PC central processing unit (CPU) market, Intel (INTC 2.43%) has been able to stage an impressive comeback thanks to its embrace of a hybrid core architecture. Starting with Alder Lake and continuing with Raptor Lake, Intel mixed powerful P-cores with power-sipping E-cores. The P-cores provide the single-threaded horsepower that's critical for applications like gaming, while the mass of E-cores boosts multithreaded performance considerably.

In the server CPU market, Intel is taking a different route. Instead of including both types of cores in a single chip, Intel will split its Xeon lineup for the first time next year. This move likely would have happened sooner, but Intel battled chronic delays in getting its current generation of Sapphire Rapids server CPUs to market. Sapphire Rapids finally launched at the beginning of this year.

While Intel will launch Emerald Rapids, the successor to Sapphire Rapids, by the end of 2023, those new chips are unlikely to move the needle. Instead, it will be the duo of Xeon chip families Intel rolls out next year that marks the beginning of Intel's comeback in the server CPU market.

Emerald Rapids will be succeeded by Granite Rapids, which will be focused on performance with its purely P-core architecture. Alongside Granite Rapids, Intel will launch a new efficiency-focused family of Xeon CPUs code-named Sierra Forest. Sierra Forest will be a critical product for Intel as it looks to reclaim its data-center dominance and fend off new competition.

Built for the cloud

There are many types of cloud workloads that don't really benefit much from faster CPU cores. Imagine a cloud-computing provider that offers inexpensive virtual servers to its customers. The workloads are generally going to be lightweight; think web servers that spend most of their time waiting for the results of database queries. These types of applications may use the CPU in bursts rather than in a sustained fashion.

For the cloud provider, packing as many CPU cores as possible into a single server rack is critical from a cost perspective. Higher core density means fewer servers and a lower total cost of ownership. That's also true for any other type of company that's running a large number of lightweight data-center workloads. If a company can consolidate those workloads onto a smaller number of systems thanks to higher core counts, it'll ultimately save money in the long run.

While Intel's Sapphire Rapids maxes out at 60 cores, Sierra Forest will feature as many as 144 cores. Sierra Forest's cores will be Intel's E-cores, so single-threaded performance will be nothing to write home about. But from power efficiency and core-density perspectives, Intel could have a home run on its hands.

Intel is claiming that Sierra Forest will provide customers with 2.5 times better rack density and 2.4 times higher performance per watt compared to Sapphire Rapids. The power efficiency will be achieved partly by moving to the Intel 3 process. Sapphire Rapids is built using the Intel 7 process, which is the new name for Intel's long-delayed 10nm process. For Sierra Forest, Intel is skipping over its Intel 4 process and going straight to Intel 3, which is a 3nm-class process. Intel 3 is expected to be ready later this year, with mass production beginning in 2024.

Sierra Forest will be followed up with Clearwater Forest in 2025, which will be built on Intel's upcoming 18A process. Intel 18A is the process that the company expects to leapfrog Taiwan Semiconductor Manufacturing Company (TSMC), which does the manufacturing for rival AMD and many other chip companies.

A necessary product

AMD already has an efficiency-focused server-chip family on the market, although it took a slightly different approach. AMD's EPYC Bergamo CPUs feature 128 cores and are built on TSMC's 5nm process. Instead of using an entirely different type of efficient core, AMD opted to use an optimized version of its Zen 4 cores called Zen 4c. The goal is the same, though: maximize core density and power efficiency.

Intel will also be going up against Ampere Computing, a start-up that designs Arm-based server chips. Ampere sells chips with as many as 192 cores, and it's been gaining some traction in the data-center market. One example: Oracle recently revamped its core-database software to run on Ampere's chips.

Sierra Forest is set to launch in the first half of 2024. The sooner the better for Intel as it battles its way back to data-center supremacy.