4MB shared L2 cache (what is it?!)

[Mac-Addict]

Well I have been looking at all the macs recently and i keep seeing (number)MB shared L2 cache, I know about ram, CPU's(not too much) and whatever.. but this thing sticks out at me, I googled it but not much came up that I could understand and the Mac I want (24" iMac) has 4MB shared L2 cache and I was wondering what it does.. sorry if i seem dumb only really been interesting in computers for 3ish years and half of it spent learning how to boot up a windoze peecee without it crashing..

 

[viperguy]

I wanted to know that too
It can't be a bad thing for that number to be high, that I'm sure

 

[Unorthodox]

A CPU cache is a cache used by the central processing unit of a computer to reduce the average time to access memory. The cache is a smaller, faster memory which stores copies of the data from the most frequently used main memory locations. As long as most memory accesses are to cached memory locations, the average latency of memory accesses will be closer to the cache latency than to the latency of main memory.

Wikipedia link

This picture should clear everything up:

 

[Mac-Addict]

Ah thanks Been really helpful

 

[Pressure]

When it is shared it means both cores can access it or some part of it.

If one core uses none of the cache, it means the other core can access the entire 4MB of Level 2 cache (thinking about the Core 2 Duo here).