Why does a computer run slow when there are many applications being used at once?

Answer 1

Well this all depends on how many cores the CPU or Central Processing Unit have. With one core and many applications it can only process things one at a time. Think of it as a book, a CPU must read through the book page by page. With many applications open it has trouble keeping up and tries to do to much at once. When you have more CPU cores it can handle more applications at once because it has more "brains" if you will to process the information. Another factor is memory, if you don't have much memory the applications sort of have to take turns accessing it because you don't have enough for the applications to all be supported at the same time. When you have lots of RAM all the applications can run at the same time without bogging each otherdown (provided you don't have a ridiculous amount open). If you need more applications open at once with no slowdown and are a true multi-tasker I recommend a quad core CPU and at least 4GB of RAM. Another thing is to always make sure you have adeqaute cooling in your PC. Remember with more Applications open everything must work harder and this generates more heat. If a CPU gets to hot the performance can drop.(This is rare and it would have to be very hot, still the cooler the better).

On a side note of how the CPU reads information. I said it's like reading a book one page at a time. A GPU(Graphics Processing Unit, video card) reads things all at once, the book reference can be as such, it rips the entire book to shreds and reads it all at once. This is why GPU's can produce such stunning graphics, apps are even being designed to run on GPU's now. They are very fast and efficient and that's why they can run at slower speeds. Hope this helped you.