CPU Speeds

Imagine an office worker is paid for the number of "sessions" he works.  Being devious, he discovers a way to make twice the money.  Instead of one 8-hour session each day, he comes in for two 4-hour sessions.  As inane and obvious as this sounds, it's what's being doing in the computer industry right now, and it's working.  When you hear something like "This is a 900 megahertz machine.", that means the CPU clock speed is 900 million cycles per second.  This measure, the "speed" of a computer, is what the general consumer has come to measure a computer by.  So, like the devious office worker, computer manufacturers have started to find ways to increase the clock speed of their computers, even if it means reducing the actual performance of their computer.  The office worker got away with it because the boss wasn't checking how long the sessions were.  Similarly, the computer manufacturers are getting away with it because the computer-buying masses aren't considering how much gets done during each clock cycle.  It's bad enough that the office worker is getting paid twice as much, but he's also probably only doing half as much work as before.  Each session has a fixed amount of overhead time at the beginning and end and the real work only happens in the middle of the session.  This same problem plagues computer chips that have been given shorter work sessions in order to increase the total number of work sessions.  They suffer from spending most their time on overhead, and the actual performance goes way down.


The first to use this cheap trick was Intel.  To get their chips up in the 1gigahertz range, they reduced the work done each clock cycle to the smallest amount possible.  This greatly hurt their performance, and AMDs chips, which did a more optimal amount of work each clock cycle, greatly outperformed the Intel chips.  But, the average, naive consumer drove the market, and Intel's was taking sales from AMD at an alarming rate.  The average consumer saw 1100 megahertz on the Intel chip and 800 on the AMD chip and were falsely led to believe the Intel chip was "faster".  What's worse, AMD soon had to start using the same cheap trick to keep their own image up to par.  So, their next generation of chips were also crippled to get their clock speed to be as high a figure as possible.


John LeFlohic

March 23, 2002