Why did cpu companies decide to pursue dual core and quad core technology?

Question

I remember faster and faster ghz was big. Then it kind of went down with dual core processors (for example 1.6 ghz dual core). How come they decided to pursue dual core and quad core technology which tops out at around 3.0 ghz instead of just continuing to up the single core processors to 4.0 ghz and beyond?

Answer 1

The CPU now doing more "ergo" with less power.Compare this to a standard bicycle against on one with speeds.More speed with less effort.

Answer 2

Four is only better than two if you can use the four. It's like the difference between a small car and a full-sized pickup. The pickup is better if you're loading it up with a couple tons often, but if your load never exceeds a couple hundred pounds, the small car would do much better as it handles better, is more fuel efficient, and has better acceleration. Previously, we had single cores chips because computers only did one thing at a time. These days, computers do multiple things at once, so having two cores gave a huge boost in performance. Question is - do you ever run enough things to truly make use of four cores? After all, if you're playing a game - you only need two cores - one to run the operating system and the other to run the game. Because of the way today's games work, you cannot get them to take advantage of more than one core. Rendering animations and videos though - the third and fourth core can easily come in handy. It just depends on whether or not you're doing it enough to justify the costs of the two extra cores.

Answer 3

IBM developed Dual Core so that they could increase the reliability of their mainframe computers, they did that by having every instruction executed twice (once on each core) so as to double check that the processor was working properly.

The concept then spread into the world of performance where instead of executing each instruction twice the extra core was used to almost double performance.

That desktop computers would become multi-processor was probably just a matter of time anyway, super-computers, mainframes, minicomputers and even PC based servers were already coming with multiple processors anyway as there was only so much performance that could be had from a single processor (at least without having the processor give off smoke).

Answer 4

Higher clock speeds get expensive. Two CPUs can achieve the same throughput going half the speed IF there are mutliple threads to work on, which is the case for many applications. Putting them in the same core allows them to share some of the same componets such as internal caches and synchronize better to external memory.

Answer 5

Because new processors can handle FOUR instructions PER CORE. Old processors only handled THREE. New processors sometimes even can handle two instructions as one. Plus, new processors use less energy, and they have WAY more L2 cache, which is extremely fast memory that stores frequently used instructions so that the CPU doesn't have to ask the RAM for stuff as often. Plus, if you run a multithreaded application, your CPU can handle 8 or 16 instructions per second, not just 3.

Answer 6

Parallel processing is a lot faster then simple processing with a single CPU. CPU's can only get so small with current technology so a way to increase performance without worrying so much about the size of the chip is to make multiple chips on a single die.

Answer 7

Operating system has been multiprocessing system for very long time. Look at your PC right now. maybe you have antivirus running, your messenger client running, your this web browser running, maybe some songs playing in your winamp or wmp. you have multiple program running at the same time.

each programs consist of threads. the program will dispatch its own threads to the computer to be executed.

Uni-core CPU can execute 1 thread at a time. that means, all programs are waiting to dispatch its thread to the cpu. while a program can only dispatch 1 thread at a time, when you have many program, you actually have many threads you can execute simultaniously. That's where multicore comes in. each core have one thread to execute, so your programs will all run smoothly. Its called thread level parallelism.

One easy way to see this is imagine you're a boss, you have 8 department giving you lots documents to sign. If you're alone, you have to work faster so you can sign them all finish in time for dinner. What if you can duplicate yourself? You have 4 you, and each of "you" only need to handle 2 department. you job finish faster, and each of "you" do not need to work so fast so all of "you" can be home in time for dinner.

Increasing the speed of one processor has its own drawback. power consumption increase, eletrical leakage between transistor increase, power loss increase, heat increase. So instead of having one processor struggling like hell, why not have multiple processor, each can work at a more effective and efficient speed. By efficient means that you dont have to run at ridiculously high frequency, power consumption is reduce, heat is reduce, power loss is reduced.

Do you know that super computers are basically a farm of old, slow CPU. In Pixar's farm of computers, each computer are no more powerful than today's CPU. But together they are a powerful supercomputer because they have hundereds of them...

So, this concept has been around for a very long time. Its just that now we can cramp 2 or 4 CPU into one package, instead of having a computer with 4 seperate CPU.

Answer 8

Energy efficiency. More mass-market appeal- regular computer users tend to have many relatively low consumption applications running at once. Plus it became kind of unnecessary to have these beefy processors when the rest of your board was bottlenecking all over the place.
BUT The speed will come again in time, my friend.

Answer 9

because the big benefits were shown by AMD to start that it wasnt all about the fastest speeds it can process but rather how much it can process per clock (mixed with higher speeds) natural it would goto dual core-quad-v8

Answer 10

They were creating to much heat by going faster and faster. The physical properties just weren't allowing that to continue.