hi, i cant understand exactly what a cache is and why it should be used, can someone help me out? i think its something like a list or table of data-blocks, isnt it? thx in advance

You can find an overview of cache in pdf format here.

a cache in the most basic sense of the word is a storage place. You can have a cache of food, or money, or anything else.

When you are talking about a cache with a computer, it is something that holds some sort of data, whether that data be code, or information. Caches have one purpose: to make things way way faster than they otherwise would be. An onboard cache on a processor can run at the actual clock speed, or some factor of it (for example, the cache on a k6-2 400 would run at 100MHz, while on my duron 900, its running at 900MHz). This is much much faster than the main memory of the computer. It is also much smaller, because it is very expensive. Hope that helped, i thought it might be more helpful than an intel document, considering you didn''t seem to have any clue what a cache was.

-arsenius
''after three days without programming, life becomes meaningless'' -The Tao of Programming

It isn''t Intel documentation. Rather it is an introduction to the general ideas behind cache. It isn''t very technical and is only ten pages long with plenty of pretty pictures.

I can testify that the document Lil put up is very useful. It talks about different cache schemes, etc. Very useful indeed and it doesn''t just cover Intel processors.

As an aside, the onboard/on-die/backside cache will run at the same clock speed of the processor. The L2 cache of the K6/k6-2 ran at 100 Mhz because it was located off the processor, on the motherboard. You could actually upgrade the cache sticks, which looked like DRAM modules (nothing big, usually from 256KB to 512KB).