User talk:4202C

Question

Do you know why Zen 5 barely performs better on average than Zen 4 in gaming and in some productivity apps, sometimes even regressing in a few of them, despite all these major architectural changes? It is very disappointing to me, I expected a Zen 2 --> Zen 3 level of increase. — AP 499D25 (talk) 13:17, 21 September 2024 (UTC)

This is hard to answer succinctly. Zen 5 seems to be more beneficial for compute-heavy tasks like in servers. AVX-512 instructions and the wider front end are at the heart of Zen 5's design. Those things do not directly translate to single-threaded workloads like gaming as no games can utilize AVX-512 instructions. Some things in Zen 5 are genuinely revolutionary like the two-ahead branch prediction but it may take a while for software to catch up and be able to properly use it.

If you look at the changes from Zen 3 to Zen 4 on paper, it does not seem like a big shift. I've heard Zen 4 described as "fat Zen 3" as it increased the L2 cache size but didn't give it greater associativity for more bandwidth, and it aded AVX-512 instructions but they were not on a native 512-bit datapath since the Zen 3 core basis was not designed with wide vectors in mind. Zen 5, on the other hand, doubled the bandwidth of the L1 data and L2 caches and made both integer and vector engines wider. From the first Zen architecture, it has relied on high cache and memory bandwidth to move data quickly especially in single-threading. The Ryzen 9000 desktop processors do seem to be much more efficient at lower power compared to Zen 4 while still having the same clock speeds or higher in the case of the 8600X and 9700X. A lot of games just like high clock speeds and AMD could have dramatically increased clocks speeds but likely chose not to because it would not bring significant benefits given the increased power draw. AMD does not rely on the brute force approach that Intel does. I have a Ryzen 9 9950X which runs much cooler compared to Zen 4 and Zen 5 seems to shine in heavily-threaded compute-forward tasks like video encoding, 3D rendering and simulation.

Zen 5 will definitely age better than something like Zen 2, which seemed revolutionary at the time it was released back in 2019. It is a building block to make the Zen architecture more future-proof in my view. From what I've heard, Zen 6 will build on top of Zen 5 and seek to address things liek latency with advanced packaging rather than doing a clean sheet core redesign. 4202C (talk) 17:09, 22 September 2024 (UTC)