Processor Types and Specifications - Upgrading and Repairing PCs - page 51

effect is that the system slows down from 233MHz to 66MHz.
All modern processors have integrated L2 cache that runs at the same speed as the processor core,
which is also the same speed as the L1 cache. For the analogy to describe these newer chips, the
waiter would simply place the cart right next to the table you were seated at in the restaurant. Then, if
the food you desired wasn't on the table (L1 cache miss), it would merely take a longer reach over to
the adjacent L2 cache (the cart, in this analogy) rather than a 15-second walk to the cart as with the
older designs.
Figure 3.2 illustrates the cache types and sizes in the AMD A10-5800K processor, as reported by
CPU-Z.
Figure 3.2. The AMD A10-5800K processor is a quad-core processor with L1 and L2 cache.
Level 3 Cache
Most late-model mid-range and high-performance processors also contain a third level of cache
known as L3 cache . In the past, relatively few processors had L3 cache, but it is becoming more and
more common in newer and faster multicore processors such as the Intel Core i7 and AMD Phenom II
and FX processors.
Extending the restaurant analogy I used to explain L1 and L2 caches, I'll equate L3 cache to another
cart of additional food items placed in the restaurant next to the cart used to symbolize L2 cache. If
the food item needed was not on the table (L1 cache miss) or on the first food cart (L2 cache miss),
the waiter could then reach over to the second food cart to retrieve a necessary item.
L3 cache proves especially useful in multicore processors, where the L3 is generally shared among
all the cores. Both Intel and AMD use L3 cache in most of their current processors because of the
benefits to multicore designs.
Figure 3.3 illustrates the cache types and sizes in the Intel Core i5 2500 Sandy Bridge and the AMD