>I remember much levity in my time at Amdahl and IBM's inability >to build a machine that scaled past 10 (?) engines. >We managed to skip past that o.k. - didn't have anything to do >with limitations in the OS - all the relevant control blocks had >plenty of width ... >Given the current powerPC architecture you'd have to think IBM >have the smarts to do massively parallel these days.
Isn't that more a question of tightly-coupled versus loosely- coupled multiprocessor systems? The first share main memory and possibly some cache levels; the latter do not. Sharing memory poses limits on the number of CPs. If that limit is exceeded, overall performance goes down due to increasing "lock-outs". Those massive CP systems are all built from 4, 8, 12 core systems and are interconnected via highspeed switches. So, these are loosely couples MP systems. -- Peter Hunkeler Credit Suisse ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
