An interesting irregularity affecting Intel CPUs has come to light, thanks to some excellent investigative work from GamersNexus. The “E” cores on the 12th, 13th, and 14th Gen Core processors are meant to improve power efficiency. This is done by handing them the less sensitive threads while prioritizing the primary threads for the P cores. Unfortunately, in most games, the P cores do the heavy lifting while their E counterparts mostly just sit around.
Metro Exodus revealed a strange discrepancy at the “Low” quality graphics preset. Enabling APO (Application Optimizer) reduces the maximum single-threaded E-core usage, improving performance and reducing power consumption. While this may sound positive, it’s not, at least not for the vast majority of gamers running Intel’s hybrid-core CPUs.
In this example, the efficiency cores were being handed threads better suited for the performance cores, reducing performance while increasing the power draw. With APO enabled, this anomaly is corrected by the Windows scheduler, reducing the power consumption by up to 230W. That’s a crazy power budget for the E-cores that are supposed to reduce the draw, not the other way around.
Luckily, this behavior is only reproducible in specific scenarios, one being the “Low” graphics setting in Metro Exodus. Intel’s latest feature for its desktop CPUs, APO, counters this behavior. Unfortunately, it’s only supported on two of the fastest 14th Gen chips, which would have been fine, except they’re mostly the same as their 13th Gen counterparts, which don’t support APO.