Level 1 and level 2 caches (L1 and L2) can provide a very fast cpu with a copy of a portion of main memory currently being accessed.

• L1 cache is more expensive/byte that main memory and takes up valuable space on the cpu chip.

  Accessing the L1 cache is typically almost as fast as accessing registers.

• The L2 cache is off the cpu chip. It may take a few cpu clock cycles to access, but may be connected to it by a special bus and accessing it is on the order of 100 times faster than accesssing main memory.