Yeah and its a shame its not,
Zen 4 despite all the rumors of underwhelming IPC uplift actually had a decent IPC uplift of like 12-13% across the board in almost all workloads at the same clock speed. And it had a nice clock speed bump so much better than Zen 3 overall.
Zen 5 has no clock speed bump over Zen 4 and almost the same clock speed. And it was suppose to be the one with the better IPC uplift. Except its not and it sucks and only like 5% at best better across almost all workloads except AVX512 and some other rare niche cases where it seems any real performance benefit.
Throwing the word IPC around isn't always ideal. IPC in what? Applications matter at the end of the day and you can either use SPEC to calculate IPC, or make up your own subset of tests that will actually impact you and make up an 'IPC' by averaging them out.
It's the latter category that have people's opinions all over the place. Zen 5 isn't '5% at best better across the board'. If you're talking single threaded, in SPEC it's 15% faster in INT and ~19% faster in FP without taking AVX512 tests into account. Even CB R23 ST shows a similar increase. Chips and cheese also got the same in their own subset of tests. But In MT, on average, Zen 5 is around 7-10% faster on average depending on PBO as there are cases of being memory bound.
But there will undoubtedly be applications that don't benefit from Zen 5's increased registers, front end and execution engines because they are instead back end/memory bound (eg. games) which even brings down the average % gain in apps. This is why some applications will show a decent increase (eg. Blender, ML tasks), some apps will see massive increases (V-Ray or anything that remotely leverages AVX256/512) while others will see little to no gains (games or lighter apps that aren't core bound and are instead memory bound). There are also some apps that get affected by higher cross CCD latencies but those are thankfully pretty rare.
Zen 4 was always going to be a bigger update 'across the board' because it had both a faster core (slight IPC from arch/cache, decent clock bump) and also faster memory with the new IO and DDR5. Consequently all apps got a decent speedup. Zen 5 doesn't have that luxury, because for all the improvements to the core they don't have a new back end/IO nor are there clock increases and unfortunately a lot of the lightly threaded apps and games are memory latency bound.
If AMD just introduced a new IO die and IF for Zen 5 and kept the rest the same, many of these consumer apps would get a larger speedup. Instead, they reworked the core significantly which instead offers very nice gains for apps that can leverage it, and i'm not talking AVX 512. It also sets the stage for future upgrades, because it's evident from the arch that there are nice low hanging fruit gains to be had through some improvements, whereas Zen 4 was nearer to being maxed out at least on the front end/execution side.
Also, since Zen 5 is even more bottlenecked by memory, X3D should theoretically offer even larger gains than Zen 4. But the average % gain will probably not reflect that because there are other bottlenecks in play when testing games. I do hear that they are going to have X3D temperature improvements and offer OC on these as well. If they can keep clocks higher than past generations, it can be a nice uplift overall.
