Intel Xeon 6300 vs. AMD EPYC 4005 SMT/HT Performance
With Llama.cpp and Llamafile's LocalScore, SMT/HT was very important to delivering better AI performance on these budget server processors. The EPYC 4005 series improvements out of SMT were the most significant out of any of the different benchmarks run and occurred on a variety of the AI workloads. Paired with AMD Zen 5's full 512-bit AVX-512 support meant for much greater performance with the EPYC 4345P mid-range processor compared to Intel's flagship with the Xeon 6369P.
With the significant performance increases in Llama.cpp from SMT there was also higher CPU power use reported for both processors tested.
In some workloads SMT/HT can hurt performance but for those areas you can always disable SMT/HT either at run-time via sysfs or from the kernel command-line when booting or your system BIOS.
Both the Intel Xeon 6369P and AMD EPYC 4345P saw significant benefits to SMT for the Embree ray-tracing kernels.
In the case of the Xeon 6369P the performance uplift from SMT was around 43% while the EPYC 4345P performance went up by 62%.