The 448G copper bottleneck has moved: Luxshare-Tech's chip-side CPC is resonance-free to 110 GHz, close to PAM4's 112 GHz, but links with first-gen external twinax-to-twinax connectors stay clean only to 100 GHz. First-gen passive copper will likely start on PAM6, under 1 m.

Liquid cooling has reached the switch faceplate, led by connector makers. Luxshare-Tech's liquid-cooled OSFP cage handles 1.6T without changing the module, but its 40 W spec was tested at 32 W and insertion force has only 0.6 N of margin after 100 cycles.

Four connector makers laid out 448G pluggable interfaces: card edge versus two-piece. All clear PAM6, but headroom above PAM4 is only 0–14 GHz, and it does not split by camp.