In terms of processor's what are Threads?

Question

In my laptop i have a 2670QM sandy bridge i7 2.2mhz with turbo boost to 3.1mhz with apparently 4 cores and 8 threads (does that mean 4x 2.2mhz = 8.8mhz or 4x 3.1mhz = 12.4mhz if it were fully maxed?) With 8GB of RAM,But what are the THREADS?

4 cores and 8 Threads, i don't get it, does each core have 2 Threads?

What are these Mythical Threads please??

Answer 1

Each core has a hyperthreaded additional core (virtual core). Hyperthreading will get you about 25-30% increased performance on HT capable applications



And no, your processor is 2.2 ghz period, base clock that is. If you are driving 50 mph in a car, and you have 3 cars in line with you doing the same, it does not mean you are going 200 mph, but cumulatively, your group has covered 4 times the distance than a single one of you can in the same amount of time

Answer 2

Intel began using "hyperthreading" technology a long time ago.

In hyperthreading, each real processor core is presented as two virtual cores, each maintaining an operation queue, and since some execution units in the core are duplicated, or not all required for certain operations, two simultaneous tasks (threads) can proceed, though due to the execution units which are contended for, there is only about 30% additional performance by running a task that uses the second thread per core.



So the 4 core, 8 thread (hyperthreaded) core can run 8 simultaneous operations, but not as quick as if it had 8 real cores. When running lower numbers of simultaneous tasks, the scheduler should optimize them to favour free cores over threads on already occupied cores - something which older versions of Windows failed to do.



Some software is tuned for threading, and divides the workload across all threads (or if you want such software to be a "good neighbour" to other things, there may be an option to use less than all threads).



For software that does not use all threads/cores, then the "turbo boost" feature is likely to come into effect, where the speed of a single core can increase to maximum turbo speed, as the heat and power usage remain at acceptable levels with the other cores idle. Turbo boost can also temporarily increase speed across more cores, so long as it remains cool enough.

Answer 3

You have 4 cores which are like separate CPUs. Each of those cores are "hyper-threading" meaning that each core also has a "fake core," making Windows see a total of 8 processors.



The term threads mean different things. For years, Windows cut up the tasks into threads for multi-tasking purposes. Hey, that is the only way to get one core to do many different things, and that is to time-share the processor. Then by the Pentium 4, they came of with the idea of getting the CPU to do some of the multi-tasking. All the resources of the CPU are not in use at any given time, so why not add extra CPU registers and pass the CPU off as two? In the Pentium 4, it wasn't as good as expected since there was a bit too much competition for the cache. While AMD was adding more and more true cores, Intel was adding more hyperthreading cores.



Another use of the term thread is for independent parts of a program. On a single-core, non-hyperthreading processor, all those parts run in the same core. But if it is hyperthreading and/or multi-core, then those parts each get their own core (whether a physical core or a hyperthreading core). Winrar, for instance, cuts up the compression into multiple threads so a multi-core CPU can run them all at the same time.



Oh, and processing speed and RAM size has nothing to do with this. Each core/thread is running at the full 2.2 GHz. For years, CPUs were measured in a "guy" sort of way, and performance meant clocking the CPU faster or making the instructions run in less clock cycles. Multi-core then adds in the "girl" way of improving performance, and that is getting more "friends" to help. That doesn't make it faster, but if the programmers cut up the work into tasks, then more cores gets more work done.



RAM speed is separate from this too. Some PCs will perform better if you have at least 2 or at least 4 sticks of RAM. They use multi-banking to allow the memory to be accessed faster by interleaving the accesses across multiple banks. But CPU speed, memory speed, and front side bus speed are separate.

Answer 4

Threads are like water pipes that take water to the Water Purification Plants(CORES) to purify(Process) them ! but a Quad Core CPU with 2.2 GHz clock speed does not mean that you have a total of 8.8 Ghz , it tells us that each core has clock speed of 2.2 Ghz and we should not sum them up :)