In March 2023 Intel laid out its data centre roadmap: 4th Gen Xeon Scalable (Sapphire Rapids) shipping, 5th Gen Xeon (Emerald Rapids) due later that year, the E-core Sierra Forest and P-core Granite Rapids planned for 2024, Clearwater Forest on Intel 18A for 2025, plus Gaudi AI accelerators and new FPGAs. The ten points below are as Intel presented them at the time, with the performance figures labelled as Intel's own claims. A short section at the end notes what happened next.
Via: Intel PR (Intel data centre and AI investor webinar, 29 March 2023)
Key takeaways
- Intel split its Xeon line into P-core parts (Granite Rapids) for peak per-core performance and E-core parts (Sierra Forest, then Clearwater Forest) for core density and efficiency.
- Sierra Forest and Granite Rapids were planned to share one platform, so server makers could design a single board for both.
- Memory bandwidth was a headline: Intel cited MCR DIMMs at 8,800 MT/s on DDR5 for Granite Rapids.
- Clearwater Forest on Intel 18A was the final step of Intel's "five nodes in four years" plan.
- The performance comparisons against AMD and NVIDIA are Intel's own published claims from 2023.
The 10 things, as announced in March 2023
1. 4th Gen Xeon Scalable and AI performance
Intel described its 4th Gen Xeon Scalable processors as the highest quality data centre CPUs it had delivered, and claimed a 4x average performance gain on deep-learning workloads compared with AMD's 4th Gen EPYC CPUs. Much of that gain comes from AMX (Advanced Matrix Extensions), the built-in matrix engines that speed up AI inference on the CPU. The 4x figure is Intel's claim on its chosen workloads.
2. Emerald Rapids
Emerald Rapids sounds like a water park, but it is Intel's 5th Gen Xeon Scalable processor. In March 2023 Intel said it would reach the market later that year.
3. Sierra Forest
Sierra Forest is not just a picturesque holiday spot; it is Intel's first E-core Xeon, with 144 cores per socket, and it was on track for the first half of 2024. E-cores trade some per-core performance for many more cores in the same power, which suits cloud workloads that run many small tasks.
4. Granite Rapids
In 2024, Granite Rapids would follow Sierra Forest, like a trusty sidekick, benefiting from their shared platform, IP and technology. Granite Rapids is the P-core part.
5. Granite Rapids memory
Granite Rapids' memory interface is fast enough to make The Flash envious. Intel cited MCR DIMMs reaching 8,800 megatransfers per second based on DDR5. MCR (Multiplexer Combined Ranks) DIMMs read two ranks at once and multiplex them onto the bus, roughly doubling the data rate seen by the processor compared with standard DDR5 modules of the time.
6. Clearwater Forest
Intel's E-core roadmap would not stop there, with Clearwater Forest planned for 2025.
7. Habana Gaudi
The Habana Gaudi 3 AI accelerator had taped in. Meanwhile, Intel said Gaudi 2 was showing a 1.8x advantage in throughput per watt over a comparable NVIDIA A100 server. This is Intel's claim for a specific benchmark.
8. FPGAs
Intel said it was introducing 15 new FPGA products in 2023.
9. Adoption
Intel said 4th Gen Xeon systems were gaining popularity faster than a viral cat video, with major OEMs, ODMs and all of the top 10 global cloud service providers on board.
10. Clearwater Forest and Intel 18A
Intel's grand finale, Clearwater Forest, was set to be built on the Intel 18A process in 2025, completing Intel's ambitious five-nodes-in-four-years strategy (Intel 7, Intel 4, Intel 3, Intel 20A and Intel 18A).
Roadmap at a glance (as presented in 2023)
| Product | Core type | Planned timing (2023) | Headline point |
|---|---|---|---|
| 4th Gen Xeon (Sapphire Rapids) | P-core | Shipping | AMX for AI, 4x deep-learning claim vs AMD |
| 5th Gen Xeon (Emerald Rapids) | P-core | Late 2023 | Same platform as 4th Gen |
| Sierra Forest | E-core | First half 2024 | 144 cores per socket |
| Granite Rapids | P-core | 2024 | MCR DIMMs at 8,800 MT/s |
| Clearwater Forest | E-core | 2025 | Intel 18A process |
| Gaudi 2 / Gaudi 3 | AI accelerator | Gaudi 3 taped in | 1.8x perf per watt claim vs A100 |
What happened next
This post records the March 2023 roadmap. For readers coming to it later, in brief:
- Emerald Rapids launched as 5th Gen Xeon Scalable in December 2023.
- Intel moved to the Xeon 6 brand in 2024. Sierra Forest launched as Xeon 6 with E-cores (6700E series) in mid-2024, and Granite Rapids as Xeon 6 with P-cores (6900P series) in the second half of 2024, with MRDIMM support at 8,800 MT/s.
- Gaudi 3 was launched in 2024.
- Intel's FPGA business was set up as a standalone unit under the Altera name in 2024.
- In September 2024 Intel said it would not use Intel 20A for products and would focus on Intel 18A.
- Clearwater Forest moved out of 2025; Intel later guided it to 2026. Check Intel's current product pages for the latest dates.
FAQ
What is the difference between P-core and E-core Xeons?
P-cores are larger, faster cores for workloads that need high per-thread performance. E-cores are smaller and more power efficient, so more of them fit in a socket, which suits highly parallel cloud services.
What does "five nodes in four years" mean?
It was Intel's 2021 plan to bring five process generations (Intel 7, 4, 3, 20A and 18A) to readiness between 2021 and 2025.
Are the 4x and 1.8x figures independent results?
No. They are Intel's own figures on workloads and configurations Intel chose. Independent reviews should be used to compare products for a specific workload.
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