AMD CEO Lisa Su’s Zen 4 teaser of the Ryzen 7000 processors at Computex 2022 was impressive, but the news that the processors would feature ‘only’ a >15% improvement in single-threaded performance left some enthusiasts feeling a bit underwhelmed. During today’s Financial Analyst Day 2022, AMD clarified that it is targeting an 8 to 10% increase in IPC for the Zen 4 processors and that the company is targeting larger gains in single-threaded performance in some types of workloads.
AMD also clarified that Zen 4 processors would have >25% performance-per-watt and >35% overall performance improvements. The company says the Zen 4 chips will also have significant clock frequency improvements, which isn’t surprising given that it has already demoed a Ryzen 7000 processor running at 5.5 GHz on all cores (albeit not with all cores under load). Zen 4 will also have up to a 25% increase in memory bandwidth per core. AMD also made several other announcements today, which you can find listed at the end of the article.
AMD’s Zen 4 disclosures today help clarify the company’s performance targets after the initial reveal. AMD’s original projections of a >15% improvement in single-threaded work led to some consternation because single-threaded performance comes as a combination of both frequency and the all-important IPC (instruction per cycle) throughput, and the relatively low single-threaded performance threshold didn’t seem to leave much room for IPC improvement. However, AMD’s clarification that the IPC gain will range from 8 to 10%, dependent upon workload, is a bit more encouraging. Whip in the company’s claims of significant frequency improvements for the 5nm Zen 4 processors, and we should see much larger gains than the baseline 15% gain in single-threaded performance in some types of workloads — remember, >15% is a “greater than” value.
AMD also shared a slide showing a greater than 25% performance-per-watt and greater than 35% gain in overall performance in a multi-threaded Cinebench benchmark. This benchmark used a 16-core 32-thread Ryzen 7000 desktop PC processor against the 16-core Zen 3 Ryzen 9 5950X. The slide is a bit misleading as it uses a non-zero axis that amplifies the gain, so keep that in mind.
The Zen 4 processors will also support up to 25% more memory bandwidth per core, a marked increase that comes from both the step up to DDR5 and likely from widened pathways in the chip to deliver additional bandwidth to the cores. That will provide quite the uplift for the bandwidth-hungry AVX-512 extensions that AMD added for Zen 4. AMD isn’t sharing any new architectural details yet, so we’ll have to wait to learn more. Here’s the rest of our coverage from today: