Abstract: There is a memory module for use in conjunction with high speed, impedance-controlled buses. Each memory card may be a conventional printed circuit card with memory chips attached directly to the card. Alternately, high density memory modules assembled from pluggable sub-modules may be used. These sub-modules may be temporarily assembled for testing and/or burn-in. Bus terminations mounted directly on the memory card or the memory module eliminate the need for bus exit connections, allowing the freed up connection capacity to be used to address additional memory capacity on the module. An innovative pin-in-hole contact system is used both to connect sub-modules to the memory module and, optionally, to connect the memory module to a mother board or similar structure. A thermal control structure may be placed in the memory module to cool the increased number of memory chips to prevent excess heat build-up and ensure reliable memory operation.