Inside Gen 13: how we built our most powerful server yet

A few months ago, Cloudflare announced the transition to FL2, our Rust-based rewrite of Cloudflare's core request handling layer. This transition accelerates our ability to help build a better Internet for everyone. With the migration in the software stack, Cloudflare has refreshed our server hardware design with improved hardware capabilities and better efficiency to serve the evolving demands of our network and software stack. Gen 13 is designed with 192-core AMD EPYC™ Turin 9965 processor, 768 GB of DDR5-6400 memory, 24 TB of PCIe 5.0 NVMe storage, and dual 100 GbE port network interface card.

Gen 13 delivers:

• Up to 2x throughput compared to Gen 12 while staying within latency SLA

• Up to 50% improvement in performance / watt efficiency, reducing data center expansion costs

• Up to 60% higher throughput per rack keeping rack power budget constant

• 2x memory capacity, 1.5x storage capacity, 4x network bandwidth

• Introduced PCIe encryption hardware support in addition to memory encryption

• Improved support for thermally demanding powerful drop-in PCIe accelerators

This blog post covers the engineering rationale behind each major component selection: what we evaluated, what we chose, and why.

Launching Cloudflare’s Gen 13 servers: trading cache for cores for 2x edge compute performance

Two years ago, Cloudflare deployed our 12th Generation server fleet, based on AMD EPYC™ Genoa-X processors with their massive 3D V-Cache. That cache-heavy architecture was a perfect match for our request handling layer, FL1 at the time. But as we evaluated next-generation hardware, we faced a dilemma — the CPUs offering the biggest throughput gains came with a significant cache reduction. Our legacy software stack wasn't optimized for this, and the potential throughput benefits were being capped by increasing latency.

This blog describes how the FL2 transition, our Rust-based rewrite of Cloudflare's core request handling layer, allowed us to prove Gen 13's full potential and unlock performance gains that would have been impossible on our previous stack. FL2 removes the dependency on the larger cache, allowing for performance to scale with cores while maintaining our SLAs. Today, we are proud to announce the launch of Cloudflare's Gen 13 based on AMD EPYC™ 5th Gen Turin-based servers running FL2, effectively capturing and scaling performance at the edge. 

AMD's EPYC™ 5th Generation Turin-based processors deliver more than just a core count increase. The architecture delivers improvements across multiple dimensions of what Cloudflare Continue reading