AMD’s Zen 3 EPYC Milan processors are 10-20% faster than Zen 2 EPYC – Zen 4 EPYC detailed
AMD’s Zen 3 EPYC Milan processors are 10-20% faster than Zen 2 EPYC – Zen 4 EPYC detailed
With Zen 3, AMD plans to deliver its EPYC Milan series of processors later this year, offering customers significant performance benefits over today’s Zen and Zen 2 EPYC offerings. We already know a lot about AMD’s Zen 3 architecture based off a leaked AMD presentation, including AMD’s plans to remove the inter-CCX barrier between CPU cores within a single CPU die.Â
With Zen 3, HardwareLuxx has reported that Zen 3 delivers an IPC boost of 15% in integer workloads and that AMD expects Zen 3 Milan processors to offer users a 20% performance boost when compared to Zen 2 when using 32-core EPYC models. With 64-core EPYC models, AMD expects Zen 3 to have smaller gains of 10-15%, as increased core counts will hamper AMD’s ability to deliver higher clock rates with Zen 3.
AMD’s Zen 3 EPYC dies will feature eight cores with a unified L3 cache. This unified cache will be 32MB in size, replacing the two 16MB caches on AMD’s Zen 2 EPYC/Ryzen dies. Instead of having two CCX’s with four cores and 16MB of L3 cache, Zen 3 EPYC dies will feature a single 8-core CCX with 32MB of L3 cache. This change eliminates inter-CCX latencies for AMD’s Zen 3 dies, which has the potential to increase Zen 3’s performance in latency-sensitive workloads significantly. Beyond that, there will be fewer instances where data needs to be stored on both L3 caches, effectively increasing AMD’s usable L3 cache size.  Â
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Zen 4 & Genoa
AMD’s Zen 4 Genoa processors will utilise a 5nm production node, and aside from that, AMD has revealed little else about Zen 3’s successor. Right now, Zen 4 is expected to continue to utilise SMT2 (Two Threads per core), and will likely see AMD move away from there SP3 EPYC socket.Â
With Zen 4, AMD’s roadmap reportedly claims that Zen 4 EPYC Genoa processors will feature higher core counts, DDR5 memory support, PCI Express 5.0, and compatibility with Persistent Memory (NVDIMM-P).Â
These claims make sense, given DDR5’s production schedules, the desire for faster PCIe connectivity within the enterprise/server markets and AMD’s inability to enable these two features while maintaining support for their SP3 socket. Increased core counts also make a lot of sense given AMD’s plans to move to 5nm, as smaller transistors can allow AMD to bring higher core counts to market without an increase in silicon area.Â
AMD’s Zen 4 Genoa processors are due to launch in late 2021 or early 2022.Â
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With Zen 3, AMD’s 15% increase in integer IPC should enable increased performance levels across a variety of workloads, and the expectation of higher core clock speeds for low core count processors should be more than enough to excite Ryzen users. The most considerable change for PC gamers is AMD’s changes to Zen 3’s CCX and L3 cache structure, as this alteration should enable smaller average core-to-core latencies, which are very valuable within many consumer workloads. Â
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