AMD 'Introducing AMD CDNA 4 Architecture' white paper

FIRST-PARTY SOURCE THAT RESOLVES THE INFINITY FABRIC DIRECTION AMBIGUITY left open on amd-infinity-fabric-link. States verbatim: 'The AMD CDNA 4 architecture comprises 8 AMD Infinity Fabric links that are 16-bits wide and fully bi-directional'; 'The Infinity Fabric links in the AMD CDNA 4 architecture run up to 20% faster generationally at 38.4Gbps for a total link bandwidth of 76.8GB/s IN EACH DIRECTION'; endnote MI350-007: 'up to 153.6 GB/s peak total aggregate theoretical transport data GPU peer-to-peer (P2P) bandwidth per AMD Infinity Fabric link' and 'up to eight AMD Infinity Fabric links providing up to 1,075.2 GB/s peak aggregate peer-to-peer (P2P) and 1,203.2 total peak aggregate theoretical GPU transport rate bandwidth performance per GPU OAM module'. Also gives the prior generation for comparison: 'up to eight AMD Infinity Fabric links providing up to 896 GB/s peak aggregate peer-to-peer (P2P) and 1,024 total peak aggregate theoretical GPU transport rate bandwidth performance per GPU OAM module' for MI325X/MI300X (CDNA 3). The 153.6 = 2 x 76.8 identity is what settles the convention: the published aggregate is BIDIRECTIONAL and the per-direction figure is half.