On November 15, 1971, Intel presented the Intel 4004 microprocessor, the world's very first commercially available 4-bit central processing unit (CPU). It was the first complete CPU on one chip. By the time, this revolutionary microprocessor, the size of a little fingernail, delivered the same computing power as the first electronic computer built in 1946, which filled an entire room.
This post takes a look at the speed - latency and throughput - of various subsystems in a modern commodity PC, an Intel Core 2 Duo at 3.0GHz. I hope to give a feel for the relative speed of each component and a cheatsheet for back-of-the-envelope performance calculations. I’ve tried to show real-world throughputs (the sources are posted as a comment) rather than theoretical maximums. Time units are nanoseconds (ns, 10-9 seconds), milliseconds (ms, 10-3 seconds), and seconds (s). Throughput units are in megabytes and gigabytes per second. Let’s start with CPU and memory, the north of the northbridge: