Core Threads

[GreenEagle]

Hello,

 

I am curious on what threads actually do on the Intel CPUs. On the I5 and I7 quad cores the I5 has 4 threads whilst the I7 has 8.

 

Thanks.

[Litargirio]

[Guest]

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[manikyath]

basicly, look at it like a production line.

 

a core is a machine that can perform tasks in that line.

multiple cores -> multiple tasks can be performed at once

 

a thread is a conveyor belt in and out of those machines.

 

without "hyper threading" theres a number of cores, each with one thread.

 

"hyper threading" adds a second conveyor belt to each machine, allowing it to take in multiple non-overlapping task.

(example: one thread needs to constantly add integers, the other thread needs to constantly multiply floating point numbers, these are non-overlapping tasks)

 

in theory hyper threading is up to twice as fast, while in reality its usually about a 10% increase over no hyper threading if all threads are appropriately used.

[Litargirio]

Basically, you can summarize a thread a thread as a stream of data that the CPU is processesing. One thread can process one stream of data at a time. Some cores have 1 thread, and others 2 threads, and they can process 1 stream or 2 streams of data at a time respectively on a single core. So i7s tend to have hyperthreading, each core having 2 threads, and i5s tend to not have it with their cores only being able to do one thread at a time. i3s on the other hand have fewer cores (two) with hyperthreading; as opposed to i5s, which tend to have 4 cores without hyperthreading, and i7s, that tend to have 4 (or more) cores with hyperthreading.

 

Although it is a bit more complicated than this, but that's the general idea.