> > So the answer to your question is that we could build a zSeries > microprocessor which is "as fast as" any other processor, but to do so > would cause us to lose the fundamental strengths in context switching, data > caching and I/O. There is alwasy a trade off between speed and capacity. > zSeries favors capacity; Intel favors speed. How much L1 cache should be > given up to increase the clock rate? How much RAS and recovery function > should be given up to improve SPECint? We have seen this situation > improve over time, and IBM will continue to improve its microprocessor > design, but zSeries cannot simply abandon strength in large working set > workloads to crank up the clock speed and/or instruction rate for workoads > with small working sets. This particularly true when the virtualization > and workload management which drive consolidation and mixed workloads is > dependent on the very hardware capabilities that would have to be given up.
It would be interesting to come up with a model that made some sacrifices to improve CPU performance, not to replace existing systems, but to supplement them. I'm sure some folk would find the tradeoff attractive, particularly as it would be software-compatible. I presume, from what you say, that Java isn't all that wonderful on zSeries? Improved CPU performance may make it so. -- Cheers John Summerfield Microsoft's most solid OS: http://www.geocities.com/rcwoolley/ Note: mail delivered to me is deemed to be intended for me, for my disposition. ============================== If you don't like being told you're wrong, be right!
