Intel Explains Why Those “Gimped” E-Cores Aren’t to Blame: 30% of Your CPU’s Power Is Just Sitting Idle

Intel VP Robert Hallock stated that the company’s efficiency cores (E-cores) in its hybrid processors barely trail the performance P-cores in gaming scenarios. According to Intel’s own measurements, the difference is within the margin of error — about 1%. The real issue, Hallock says, isn’t hiding in the silicon — it’s on the software side and in the workload scheduling mechanisms.

Hallock reminded everyone that many reviewers and enthusiasts have seen frame rate gains after completely disabling the E-cores. In those experiments, the system could indeed deliver higher FPS, but the exec argues the reason isn’t that the little cores are slowing down the game — it’s that the software and the OS scheduler simply didn’t know how to properly distribute threads across the different core types. When E-cores are turned off, the scheduler has no choice but to guarantee that the workload lands on the fast P-cores — hence the perceived speedup.

Hallock admitted that Intel shares part of the blame for this confusion — the company hasn’t always provided the necessary software to the market on time, nor has it synchronized hardware launches with OS-level improvements. He’s talking about situations where Thread Director and related mechanisms were either completely absent in early Windows builds or weren’t working correctly. Under those conditions, the scheduler could send latency-sensitive gaming threads to the E-cores or randomly bounce them between clusters, leading to inconsistent frame times, micro-stutters, and an overall drop in performance.

The key takeaway is that many modern game engines still operate under the assumption that all CPU cores are identical. When that assumption meets a hybrid architecture, you get dispatch errors, thread imbalance, and inconsistent render times. Hallock estimates that hidden performance headroom is in the 10–30% range — that’s how much performance a game could be leaving on the table simply because it hasn’t been adapted for a specific CPU. Intel insists that the hardware is already capable of competing with the best gaming solutions on the market, including rival chips with 3D V-Cache, but as long as developers and platforms haven’t learned how to properly make use of the hybrid design, owners of CPUs with E-cores will periodically see results that fall short of expectations.

Hallock specifically emphasized that the PC gaming market, especially enthusiasts, systematically underestimates the role of software. You can throw a more powerful CPU or GPU at the problem, but you’ll keep “losing” tens of percent of your frame rate if the game doesn’t understand what kind of processor it’s running on. While Intel is shifting some of the responsibility onto third-party engines and OS schedulers, gamers continue to get an inconsistent experience on hybrid-chip systems. Whether developers are ready to widely adapt their projects for heterogeneous cores, or if that burden will fall on the next generations of processors and smarter software — only time will tell.

Have you noticed any difference in smoothness or frame rates after forcibly disabling E-cores on your own system? Share your observations in the comments.