S/390 cost performance considerations for packaging choices

The S/390 architecture lends itself to an MCM package solution that provides the best performance at the lowest cost for the maximum SMP system. In this paper we develop a cost performance criterion that can be used to evaluate several MCM structures and materials. The results of this comparison show that a Glass Ceramic based MCM is cost performance equivalent to a polyimide thin film based MCM for off chip bus speeds up to 250 MHz. At this range of frequency this work shows that an Alumina MCM implementation has 17% less cost performance. In addition, the trend curves shown in this study indicate that polyimide thin film MCM structures will be the best cost performers in future systems where the off chip bus speeds exceed 250 MHz.