Well, it's both about what hardware you bring and how you are using it.
LLR runs best with FMA3 support or better. And SoB-LLR operates on 30 MBytes of FFT data at the current search range. If the CPU can't cache all of these — or can, but the user didn't take the necessary configuration steps —, the CPU will merely trod along with more or less of a handicap.
On the Intel side:
Haswell-EP (and its derivative, Broadwell-EP) with >12 cores manage, but they are old and therefore energy-intensive to operate. Before Haswell(-EP), there is no FMA3 support.
Skylake-SP and its derivatives presumably need about >22 cores in order to have sufficient cache (because there is a lot less L3$/core than in Haswell-EP). But last time I checked, LLR2 was unable to utilize respectively many software threads on Skylake-SP and its ilk. It hit a ceiling at about 8 threads, hence, the numerous AVX-512 units idled a lot. I haven't checked for quite a while now whether or not these scaling issues have been addressed in the meantime.
All other Intel CPUs just don't have enough cache. SoB-LLR is bottlenecked by memory accesses on them. (Plus potential additional bottlenecks, depending on CPU generation and the user's setup.)
On the AMD side:
Zen 2 with its TSMC 7nm process and native 256-bit FMA3 support was nice and all, but has got far too small CCXs for SoB-LLR (4 cores, 16 MB L3$). Zen 3 (same manufacturing process and same vector instruction set, but double CCX size) is what you would prefer over Zen 2 for SoB-LLR.
Zen 4 brings the same CCX size as Zen 3, such that SoB-LLR fits into the CCXs of both of them. But Zen 4 is also manufactured on a newer process (thus, is even more energy efficient), and has got some core architecture tweaks (such as AVX-512 support) which successfully improve per core and per clock throughput versus Zen 3.
Comparing big AMD CPUs with big Intel CPUs, Zen (2,3,4)'s division into CCXs is one of the reasons why they are so fast and efficient. But for the same reason, the user needs to go through some more hoops to set up an application like SoB-LLR on Zen (2,3,4), because Windows and even Linux do not schedule the tasks appropriately. With Linux and AMD server CPUs, you get almost optimal results with respective BIOS hints to the OS, but intervention at the application software level (i.e. logical CPU affinity) still brings best results. So the user has a price to pay for Zen (2,3,4)'s added complexity compared to Intel gear.