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View Full Version : What level of multitasking can a PC do?


Dinosaur
02-09-2002, 11:12 PM
Excuse my ignorance of PC CPU functions at the nitty-gritty level and similar ignorance of the innards of OS operations on a PC.

On a Mainframe, the OS can run 5-10 or more programs on a time slice basis, and have say 5 disk I/O operations, 4 Tape operations, 3 printing jobs, and many keyboard input devices running concurrently. While two or more programs will not execute concurrently (unless there are multiple CPU’s), many I/O operations function concurrently with no requirement for CPU attention until there is an error interrupt or an I/O complete interrupt.

On a PC with three physical disk drives, can three disk data transfers take place concurrently? Can the CPU transfer data to printer memory and concurrently transfer data to/from a disk?

Is concurrent I/O & computing limited by the CPU & motherboard capabilities, or by OS capabilities? For example can Lunix or Unix run multiple devices, while Win9x cannot? Does NT or IBM OS/2 have more multiple I/O capability than Win 9x?

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mjc
02-10-2002, 12:15 AM
Is concurrent I/O & computing limited by the CPU & motherboard capabilities, or by OS capabilities? For example can Lunix or Unix run multiple devices, while Win9x cannot? Does NT or IBM OS/2 have more multiple I/O capability than Win 9x?




YEP...it all depends on the OS....and for drive functions, the type of interface (IDE/SCSI)


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mjc
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Ghost_Hacker
02-10-2002, 08:14 AM
I would also add that there are 2 types of multitasking cooperative and preemptive.

Preemptive multitasking is what mainframes( mutiuser computers) do and is consider "real" multitasking. Whereas Cooperative multitasking is what some "macro"(single user)computers do. However, in a single user enviroment it isn't nessary to do "real" multitasking.

All current Windows operating systems,Unix and Linux are "preemptive". Mac's are cooperative but OS X because of it's "unix" background should be able to do premptive mulititasking.