HI,

Can any one please clear me out how Multithreading is useful in Uniprocessor system(Except the I/O event scenario).as the main aim of multithreading is parallel processing.

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Neither of those links seem to be valid. They link to

"Multithreading on a uniprocessor machine" really isn't for "parallel processing." You are not multiplying the CPU resource: you are dividing it.

The main thing that multithreading gives you is the opportunity to overlap input/output (I/O) operations. Most processes actually spend most of their time waiting on something-or-other, and multithreading enables other units of work to be dispatched while others are waiting.

Often, what actually happens is that each process wakes up, evaluates the result of the I/O operation that it had just completed, then sets-up and starts another I/O operation and goes back to sleep again, having consumed only a negligible amount of CPU time in the interim. (We call these workloads, "I/O-bound," since their completion time is mostly tied to the speed of the I/O subsystem.

Some multithreaded scenarios also involve so-called "CPU-bound" activities that really do burn-up all the CPU time that they can get. By assigning an inferior dispatching-priority to these, we allow them to "run in the background," consuming their full time-slices whenever they can get them but immediately yielding control of the machine to other, more-interactive tasks.

As long as the various units of work are not competing for the same resource, and as long as their combined impact on the machine does not exceed the infrastructure's ability to actually handle it, multithreading does afford the opportunity to do more work in less time ... [only] in properly-designed scenarios.

Hi,

Sorry for the bad links;Hope this helps.
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Linux is a true multithreading OS. Uniprocessor machines of today use processors with multiple cores, each of which can handle threads. On Intel processors (Core i3, i5 and i7) each core can handle (2) threads. With certain programs you can specify the number of cores to use, such as with will use 6 cores to compile the program.

But multithreading only works if the software can take advantage of it. Programs like word processors, web browsers, and photo editors typically will only use one processor core.

I would just correct 1 thing. Desktop i5's are non hyperthreaded and only do 1 thread/core (as they're quad core vs. the hyperthreaded dual core i3's and quad core hyperthreaded i7's), as well as mobile core-i5 H-series chips (which are also quad core), although mobile U-series chips are all hyperthreaded.