Not a simple binary equation
By Charles Miller

Many computer technicians, such as me, get unfairly labeled as “binary thinkers.” Computers are binary devices: on or off, right or wrong, up or down. That carries over to the technician’s thinking; things either work or they do not work. Paradoxically, though, the innards of computer hardware are anything but binary.

For example, take the Central Processing Unit (CPU) chip. This heart of the modern computer has millions of transistors sealed inside one chip of silicon. The newest Intel Quad-Core Itanium chip has 2,000,000,000 (that is two billion) transistors.

These CPU chips are sold and priced by their clock rates. A 3.0 GHz (gigahertz) one costs more than a 2.8 GHz one, which sells for more than a 2.4 GHz chip of the same design. Something most buyers do not understand, because it is so difficult to explain, is that all three speeds, 3.0, 2.8 and 2.4, are of the exact same design and they might all have come out of the same batch of chips.

Chip makers such as Intel or AMD do not make three different chip speeds by design…they just make chips. For a given CPU chip, clock rates are determined at the end of manufacturing through actual testing of each one.

One batch of computer chips might have produced three or more different clock speed chips, all in the same manufacturing run. Now here is where things get really interesting. The reason some chips test faster than others is that the slower chips have higher numbers of bad transistors in them, but they still function perfectly.

Like water running downhill, if electrons passing through a CPU can find their way through the maze of transistors, good ones and bypassed bad ones, the chip will work. It just takes longer with higher numbers of bad transistors, resulting in that CPU being labeled as slower clock speed and sold for a lower price.

I can imagine some readers are going to find it hard to swallow that their brand new computer was sold to them with thousands of bad transistors in its CPU, but that has always been the case. It is also the case that some other electronic components in the computer are not as binary as some believe.

Inside the computer, the motherboard is populated with large numbers of capacitors. Many are the times that somebody has accidentally snapped off one of these while working on the computer. Surprisingly, in many of these cases, the computer will still run just fine. Most of the electrolytic capacitors on a motherboard are involved with the on-board audio and/or video and are vital, but the bulk of the bypass capacitors are there to keep internal data signal transients or external radio frequency sources from causing problems.

Even with several of these failed, worn out, or even broken off the motherboard, it is possible for the computer to work fine. Of course, if you begin to have intermittent problems, then you might want to remember if you broke any parts off your motherboard.

The things I have described here are also a part of the normal aging process of a computer. The individual electronic components that make up the computer do fail on a regular basis, yet so long as that component was not vital, the computer can often continue to function, albeit a bit slower.

This is something most computer users do not readily accept, probably because it is an intangible. It is hard to see because it is not a simple binary equation.


Charles Miller is a freelance computer consultant, a frequent visitor to San Miguel since 1981 and now practically a full-time resident. He may be contacted at 044 (415) 101-8528 or email FAQ8 (at) SMAguru.com.