AMD Zen 5 CPUs Allegedly Going to Offer Only 10% IPC Uplift, Claims Lenovo Manager

AMD’s Ryzen 9000 processors are among the most anticipated chips of this year. Based on the Zen 5 core architecture, these CPUs are expected to bring the next leap in PC performance, including AI and hybrid core designs. Till now, we’ve mostly reported on rumors claiming massive generational uplifts with Zen 5. The rumor mill claims these chips will be 30-40% faster than existing Zen 4 parts, core-to-core, at least in certain workloads. This new rumor alleges otherwise.

Lenovo’s China Manager has questioned the 40% IPC bump, claiming that Zen 5 offers a relatively slim 10% improvement over Zen 4. Cinebench R23 1T gets a larger uplift, likely due to the powerful integer pipeline on the next-gen Ryzen cores. Previously, @Kepler_L2 had reported that Zen 5 is 40% faster than Zen 4 in the SPECInt single-core benchmark.

Zen 4 offered a 13-14% IPC uplift over Zen 3, most from improvements to the front end, load/store, and branch prediction. From what we’ve heard about Zen 5, the front end will feature wider cache buffers, an improved “Zero-bubble” branch predictor, and a wider dispatch. The decoder is relatively outdated, and we expected an expansion with Zen 5, but nothing has come to the surface.

Most macro-ops are (likely?) fetched from the op-cache to save power and performance. On the backend, we are looking at an expanded integer execution and a consolidated scheduler. Things are less certain on the floating-point side. Rumors claim several 512-bit ALUs, but that seems a little over the top. An additional FMA slot is the least I expect.

The load/store bandwidth is expected to go up to 4 loads (previously 3), backed by a faster “Ladder Interconnect” (Infinity Fabric upgraded?) and memory controllers. If all these architectural improvements are legit, Zen 5 should offer at least a 15-16% IPC uplift over Zen 4. But then again, none of this is official. We’ll have to wait and see.

AMD is expected to reveal its Ryzen 9000 processors powered by the Zen 5 core at Computex next month.

Via: WCCFTech.