A while back, we reported that Intel’s 14th Gen Raptor Lake Refresh can offer a performance uplift of up to 20% using the mysterious APO (Application Optimizer) technology. Sadly, it is only supported on the higher-end 14th Gen processors: The Core i7-14700K and the i9-14900K. The 13th Gen CPUs don’t support APO, not even on the Core i9-13900K or 13900KS. Hardware Unboxed investigated APO and found that it works by enhancing the clocks of the E-cores in gaming workloads.
Most games don’t utilize the E-cores, even seeing performance regression with them running in the background. This isn’t because they are useless but because the Windows scheduler still isn’t fully mature enough to deal with heterogeneous CPUs. Instead of limiting the E-cores to background processes that aren’t latency sensitive, it tends to assign one of the primary game threads, lowering the resulting performance.
Hardware Unboxed reached out to Intel to verify if APO is really limited to the 14th Gen CPUs, and they got an answer. It is. Intel’s 12th, 13th, and 14th Gen processors are based on the same platform with more or less identical cores and architecture. Raptor Lake increased the L2 cache for the P-cores, thereby upgrading Golden Cove to Raptor Cove, but the Gracemont “E” cores have remained identical throughout.
Intel APO is implemented on a scheduler level. You need to install the latest BIOS firmware and proceed with the APO app. However, if you have a 12th or 13th Gen CPU, the app refuses to connect. I suspect that like the initial block on AVX512, this is a software-level restriction.