Your 8-bit adder will have to wait ~225 CLKs (possibly x 2) to get the data it needs to add. Add a ton of transistors to intelligently prefetch and cache will

Your 8-bit adder will have to wait ~225 CLKs (possibly x 2) to get the data it needs to add. Add a ton of transistors to intelligently prefetch and cache will in some cases decrease those 225 CLKs. A great deal of transistors are added to cache and cache intelligence to get around the terrible latency of DRAM.