pc
thinkcentre S series
http://www-132.ibm.com/webapp/wcs/stores/servlet/CategoryDisplay?catalogId=-840&storeId=1&langId=-1&dualCurrId=73&categoryId=2580523
runs Windows XP
mid-range
iSeries
http://www-1.ibm.com/servers/eserver/iseries/hardware/medlarge/890/index.html
runs "mini-computer" / mid-range operating systems that can function as servers
in a network.
Runs OS/400 (descended from AS/400), the ever popular Linux, Windows Server
may run IBM-flavor Unix called Aix.
delivers multi-processing, the simultaneous execution of multiple
threads with shared access to RAM
all with coherence (imagine if your Wintel PC could run with 16 Pentium-4s).
Such business servers typically include error correction memory,
special disk configurations that can tolerate
an occasional disk failure. The emphasis is on reliability, redundancy.
Can run multiple different operating systems concurrently by fencing off resources
such as memory, known as logical partitioning.
mainframe
http://www-1.ibm.com/servers/eserver/zseries/
zSeries runs the z/OS mainframe operating system and Linux.
until the 1990s mainframes were expensive partly because they were liquid-cooled
and needed special elcetric power, raised floors, air-conditioning
and large bulky cabling.
With today's miniaturization they look more like large commercial
freezers but have shed
most of their distinguishing physical characteristics. ie. normal
floor, thin cables.
Many of the features in today's midrange originated in mainframes.
Mainframes excel in arrays of discrete units (own processors, memory, I/O paths)
harnessed together to access a shared, common pool of disks, tapes,
optical platters.
Special IBM software, working in co-ordination with the operating system(s)
allows incoming work to be scheduled on one to many of 200 or more
processors , prioritized, controlled, monitored, measured
in a highly secure 24/7 setting with minimal human oversight. |
