According to here (https://www.techpowerup.com/review/intel-core-i3-12300/2.htm...) The i3 uses a different die ("H0" vs "C0" of the 12900K). The "H0" supposedly has 6 P cores and no E cores. This meshes well with Intel's product stack - everything 12600 and down is maxed out at 6P+0E.