The RTL8126-CG is a PCIe 3.0 x1 to 5GbE controller, succeeding RTL8125 chips. The RTL8157-CG, a USB 3.2 Gen2 to 5Gbps Ethernet controller, updates RTL8156(B)/(BG) 2.5GbE USB controllers. Meanwhile, the RTL8251B-CG, a single-port “PHYceiver,” supports 10/100/1000/2500/5000 Mbps links, consuming under 1.5 watts compared to 0.7W for 2.5 GbE networking. Notably, all maintain compatibility with Cat5e cables at higher speeds. These controllers, housed in 8x8mm QFN packages, represent Realtek's advancements, offering faster Ethernet connectivity and power efficiency, catering to modern networking demands in compact, energy-conscious devices.
