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Ninjabear
12-02-2010, 12:58 PM
Hi There

It's been a long time since I've posted.

What I was wondering is the difference between the L1-3 cache.

I read a bit about that and that it can fetch data faster than ram and the main tool for cache is to perform instructions better by storing small amount of data in the caches.

So if data cannot be find in the L1 and moves onto L2 and then lastly L3.

My question is why can't they simply increase the size of L1 cache and get rid of L2 and L3?

Sweep
12-02-2010, 01:06 PM
This is by design as the three caches do different things. From Wikipedia.

Most modern desktop and server CPUs have at least three independent caches: an instruction cache to speed up executable instruction fetch, a data cache to speed up data fetch and store, and a translation lookaside buffer used to speed up virtual-to-physical address translation for both executable instructions and data.

linw
12-02-2010, 01:33 PM
The simple reason for not just having a large L1 cache is cost. It is difficult/costly to put large amounts of high speed RAM on the CPU die. So, we get into the old trade-off situation.

Don't forget Google is your friend.

Thebananamonkey
12-02-2010, 04:52 PM
http://en.wikipedia.org/wiki/L2_cache

http://en.wiktionary.org/wiki/initiative