ELE375: Computer Architecture

These are some general themes from my computer architecture class. Related articles: How computers work

Small is fast

With less memory, it is easier to find a particular element, and fewer bits are needed to access an element. Think about finding a book in a library or in a small pile.

Memory: Large, fast, cheap. Choose Two.

Everyone wants a huge amount of fast, cheap memory. Sorry, but it can't happen.

• RAM: fast and large, not cheap (dollars per megabyte).
• Hard drives: large and cheap, not fast.
• Registers: VERY fast, small and expensive. The extreme speed cancels out the large and cheap factors :)

Clock speed isn't everything

Clock speed just measures how a cycle is on the computer. But how many cycles are there per instruction, and are they big or small (RISC vs. CISC)? How is the computer pipelined? What about registers and cache, or out-of-order execution and branch prediction? There are many things to consider. Intel vs. AMD is the canonical example.