Al-Si cast alloys account for 80~90% of the world’s castings and HPDC specifically accounts for more than ~60% of this subset due to cost competitiveness for mass production. However, the thermal and electrical conductivity properties of Al-Si alloys are only ~50% of pure Al in the as-cast condition, which can only be increased to ~70% with resource-consuming heat treatments. Improving conductivity properties with decent strength can lead to higher performance and/or lifespan for applications such as electric vehicle powertrains, electric motor rotors, internal combustion engines, heat exchangers, etc. Alternative Al eutectic systems such as the Al-Fe, Al-Fe-Ni, Al-Ni, and Al-Ce systems offer pathways to achieve ↑ conductivity & ↑ strength for castable Al alloys. Current research focuses on establishing the significance of intertwined, hierarchical microstructural parameters that govern conductivity, strength, and castability, to provide a foundation for alloy development strategies.