The ASRock X870 Steel Legend WiFi is the objective winner of this comparison, securing victory in seven out of thirteen evaluated specifications. Its most impactful advantage is a 100% increase in maximum memory capacity compared to the alternative. While the ASRock B550 Steel Legend holds its own in three categories, it falls behind the newer model in the majority of technical metrics, making the X870 variant the superior choice for users prioritizing expanded system memory.

Choose the ASRock X870 Steel Legend WiFi if your primary requirement is high-capacity memory support for demanding workloads. Conversely, select the ASRock B550 Steel Legend if your specific build configuration relies on a higher count of PCIe x1 slots, where it maintains a 100% advantage over the newer board. These distinct hardware benefits allow you to align your motherboard selection with either memory-intensive tasks or specialized expansion card requirements.