What type of menory is used to temp store info that the computer is currently working with?

Answer 1

There are several. The hard drive is a kind of memory. It is non-volatile, meaning when you turn off the computer the information stays.

From there it goes into system RAM, the sticks that stick up out of your motherboard. RAM stands for Random Access Memory, and that's what these are. They are designed to accept information quickly, provide access to the information quickly, and erase it quickly. With current technology they are also volatile, meaning they lose the data when the power goes off. This is the workspace for the computer.

From there it is read by the CPU. This chip is really a massively powerful calculator. In fact, its so fast that it has its own memory chips built in. And not just one, it can have up to three separate groups of RAM. These are called the CPU's cache (pronounced "cash".) They are optimized for the CPU to retrieve data extremely quickly and write it extremely quickly. The cache's purpose is to have everything the CPU needs at a moment's notice. If you remember the Intel CPU called the Celeron these were cheap because they had very little cache. At first they had toolittle and it really restricted the CPU's performance.

After the CPU does its computations the result goes back through its cache and probably goes back to system RAM to be temporarily stored for more computations (like when starting up a program) or for some other program to refer to it.

No, you're not done yet. Microsoft knows how important system RAM is (people were very unhappy with how much RAM Windows Vista needed, and Microsoft specifically addressed this complaint in Windows 7) and Windows tries to keep as much free as possible. Less important information in RAM is "swapped out" to a temporary holding spot on the hard drive. Terms associated with this are virtual memory, swap file, and pagefile. Data is also swapped out if you don't have enough RAM - in this case the virtual memory acts like an overflow. Has anyone ever told you "more RAM makes your computer faster"? It doesn't, technically - it helps reduce swapping from RAM to the (much, much slower) hard drive so your computer can run at its best speed.

Still not done! Computer manufacturers have realized how very greatly cache helps, acting as a temporary space or a fast retrieval space as it does. Hard drives all come with their own cache now. This cache acts like a buffer so that Windows can throw a big chunk of data at the hard drive and not wait for it to actually be written. The hard drive reports "I got it!" when actually the data is in the hard drive's cache. Have you heard the term "flush the cache"? That refers to getting all the data in the buffer written safely to the hard drive.

Cache, buffer, flash, RAM... if you are thinking "aren't all these memory that store data?" you're right. The system RAM, the CPU's caches, and the hard drive's cache are all volatile. The virtual memory (the swap file) is not really volatile, because it is an actual file on the hard drive, but its more like a one-time-use place. The data in the pagefile is not intended to be reused, just used and changed, like system RAM. The hard drive and your flash drive / portable memory stick are nonvolatile. The hard drive stores data by magnets, and the flash drive stores it by NON-volatile RAM. Why not make the hard drive and system RAM from the same stuff as your flash drive? Currently, non-volatile flash is far more expensive than a hard drive, byte for byte; its much slower than system RAM; and it actually wears out after thousands of write-erase cycles.

By the way (did you think I was done?) now there is even a level of cache meant for the operating system's use! Two similar and somewhat competing systems just came out, Windows' Readyboost and Intel's Turbo Memory.