Update Rome models (#491)

tools/topo_expl/utils.cpp

@@ -682,6 +682,8 @@ ncclResult_t initTransportsRank_1(struct ncclComm* comm, struct allGather1Data_t
     allGather3Data[rank].nc = 4;
   if (comm->topo->nodes[GPU].nodes[idx].gpu.gcn == 910)
     allGather3Data[rank].nc = std::max(allGather3Data[rank].nc, 4/ringGraph.nChannels);
+  if (ringGraph.nChannels > MAXCHANNELS/2)
+    allGather3Data[rank].nc = 1;
   allGather3Data[rank].tree.pattern = treeGraph.pattern;
   allGather3Data[rank].tree.nChannels = treeGraph.nChannels;
   allGather3Data[rank].tree.sameChannels = treeGraph.sameChannels;