Processor Cores and Threaded Programs

[Skyhawk Delta]

When are more cores actually needed, and why do some programs benefit from more cores while others do not? As of now, my knowledge of this that games really don't see much benefit from more cores, and I feel like that is the extent of many PC gamer's knowledge. We are advised to buy the 3570K and not the 3770K, and that about sums it up. Why is this the case, and what would necessitate an upgrade to a processor with more cores and/or hyper-threading? I'm hoping that someone or several people will be able to provide a detailed explanation of this. I want to expand my knowledge this area, and help some other people do the same.

[killerx525]

Usually it is the way a program has been written that determines how many cores it can use. If you bought a 3770K for just gaming purposes you will see no benefit at all and it would make sense to purchase a 3570K or 3570 which would basically perform exactly in games like the 3770K.

[Christian]

More cores and threads are better for video and photo editing suites. Especially very large photos, or high quality video, which required a lot of CPU power and RAM in order to process changes and hold data. Video converting smashes the CPU, and the faster the CPU, the shorter amount of time it will take to convert a video.

[Torand]

Say i write a program. By default it has 1 thread. If i add more threads, the process will in theory be carried out faster or/and can have multiple things on the go.

Games at present don't see an advantage over Quad core as games, more the games engine, has not been written more more threads. As games get more demanding in physics calculations and NPC's algorithms, stuff in which is bared on the CPU, you will get more threads being used and taking advantage of more cores.

Where you get the need for more threads, for example in 3D rendering, CAD, modelling and physics calculations, you see an advantage as the more threads you throw at it the better! It will dynamically add performance as it will just create another thread for the next render sector that it needs doing. More threads, more things it can render at one time.

Correct me if i am wrong but this is how i think it is:

Your processor deals with that 'thread' of instructions in one go, which is stored into the L1 cache before being processed then sent to the RAM where the output sits within its byte space.

The advantage of the i7 is Hyper-threading (in which the i3 uses to emulate a quad core when it has only 2 cores). 4 physical cores in which you could 'see' and 4 logical, which aren't really there, so you have 8 cores in total seen by your OS. Each core then acts as 2, layering the threads and dealing with 2 at a time.

IF however the i7 (or i5) sees that a process is only using one core, it will give the thermal and clock headroom of the cores that aren't being used, to the core that needs it to get that task off that core and completed faster, thus Turbo boost was born.

Sorry if it is a little vague if i was speaking i would have probably got the point across i tend to loose myself behind the keyboard as ideas and bits pop into my head and my fingers cannot go fast enough.

Here is some more reading:

http://en.wikipedia.org/wiki/Thread_(computing)

http://en.wikipedia.org/wiki/Multithreading_(computer_architecture)

http://en.wikipedia.org/wiki/Multi-core_processor