> On Sun, 2003-02-16 at 17:32, Mark Darvodelsky wrote: > > But the question still does not appear to be answered - why does the > > mainframe have to run at such a low clock speed? > > > > Perhaps someone with some hardware knowledge could explain it? Why can't > > the clock be cranked up to be the same speed as the latest Pentium? > > This has everything to do with heat dissipation and the media capacity > of the processors themselves. Does IBM have the capability to make > processors that will run faster, yes. Will they, not without due > overcompensation. Look at the history, the AT was running at 6Mhz while > every other AT clone manufacturer was running at 8 and 12 - the same > went for all of the IBM x86 boxes made.
It's easier to go faster when you have newer technology. That said, the original PC and PC/XT were pretty feeble, using the 8088 when the 8086 was available first, and faster. > > Most of us mainframe guys understand its inherent advantages, but as > > someone has already commented, it often just doesn't wash with management > > if a cheap Pentium outperforms a million-dollar mainframe. > > Convert your favorite CICS app to the Windows world, connect 25000 > concurrent user sessions and watch the clock - then come back and tell > us how long the Intel box(ES) stayed alive under that realistic load. It > boils down to this, at the end of the day the mainframe is still running > when the Intel units have had to be rebooted multiple time. This goes > without stating that the number of Intel machines it would take to Linux is Linux. Don't confuse Windows' reliability with the reliability of IA32-based boxes. They can be built to be very reliable indeed, and even the cheapest PC clones today are much more reliable than mainframes of years gone by. -- 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!
