This paper proposes a semi-completely-connected bus, called SKB, to alleviate the long-wire and pin-neck problems against on-chip systems through a small diameter and dynamic clustering. Dynamic clustering allows to reduce the traffic to the per-cluster units such as the global interconnect interface, as compared with the static clustering fixed in hardware. We derive a 2 ⁿ -node semi-complete (SK) graph from a simple node-partitioning. An SKB is produced from the SK graph when we replace the links incident to a node by a single bus for the node. The diameter of SKB equals 1 (bus step), though the bus length is rather long, O (Ö{2ⁿ})(\sqrt{2^{n}}) . Simulation results show that relative to the hypercube with the link delay of 1 clock, the SKB’s bandwidth is about 0.97 and 0.14 assuming the bus delay of 1 and 8 clocks, respectively, that increases to about 4.57 and 0.71 with the dynamic clustering.