Ow, That Hertz! (or, Keep It Cool, Man!)

Our next tip has to do with cycles.  These are not bicycles, but clock cycles inside electronics.

We are all aware of the fact that electronics continually follow 2 trends:

•  They get faster & more powerful
• They get smaller

Computers are the classic example of these trends.  Early computers would take up a large room.  They became smaller and smaller until home desktop computers came out in the 1990s.  Through the 1990’s, they also became faster and more powerful.

The key to a computer’s speed starts at its processor, the “brain” of the machine.  Its processor ran at a speed of 4.77 MHz (Megahertz).  This was the clock pulse of a machine – controlling the timing of the electronics.  A Hertz has a mathematical value of 1/s.  The means one signal pulse per second.  Standard NTSC television (cable TV) has a speed of 60Hz.  This equates to 60 frames per second.  Anyone who does video editing will tell you that this allows the frames to be changed quickly enough that the human eye can not detect that they are actually watching a series of changing still pictures.  This of course gives the illusion of seeing live full motion.

Modern HDTVs display at frequency of up to 120Hz (120 frames per second), some even claim up to 240Hz.  You won’t see any screen flicker watching those!

So that early computer sent signals at a rate of 4.77 Megahertz.  A Megahertz is 1 million signals per second.  That sounds really fast, no?  That should have been fast enough to run anything!  Keep in mind that is in the form of a digital clock pulse.  Each instruction has to be broken down digitally into a series of 1’s (on) and 0’s (off).  These instructions and data have to be carried on the main circuit of the computer which connects the CPU, memory, and devices.  Simply printing the letter A to the screen involved a series of instructions that had to be broken down and carried on the main circuit.  Here is the process in simple terms:

1. The user types the letter A on the keyboard.
2.  A special chip, called the Interrupt Handler, contacts the CPU, “interrupting” what it is doing to get its attention.
3. The CPU has to read (from the computer’s memory) the driver information.  (The driver is the series of instructions on how to control and communicate with a device.  In this case, the keyboard.)
4. The CPU processes the instructions, converting the letter A, digitally.
5. The CPU then reads the driver for the video card.
6. The CPU then processes the instructions to send the letter A to the video card.
7. The letter A displays on the monitor.

As you can see, this simple task takes a lot of instructions, which need to be carried back and forth on the main circuit as a series of electronic signals.  Those users of early computers (even into the 1990’s) would see sometimes a “lag” when they were typing quickly.  This was the system’s inability to keep up with the speed of the user.  You see, Hertz is actually a measurement of frequency.  In addition to being a measurement of the “clock pulse” of the computer, it is also a measurement of how many instructions can be carried and processed per second.  In other words, how frequently these instructions and data can be acted upon.  If you relate that to your heart rate, it runs at a certain “speed” when at rest.  (Also a frequency, measured in beats/minute).  When you do “work” (i.e. exercise) your heart rate increases, and the support systems work harder.  Naturally, as computer software became more complex with more options, the number of instructions increased significantly.  Therefore, the system needed to run faster.  (Of course, the CPU wasn’t the only thing that needed to increase in “power”, but the support components – memory and devices – needed to as well. 

Believe it or not, a very big driver for the continuing increase of the power of computers and components where a specific niche of users and the software they used.  That was that of the gamers, wanting video games that were much more complex with improved graphics.  This is still a big driver in the growth of computers and electronics today.

So that leads us to the theme of this article’s topic.  In the 1990’s and early 2000’s, there was a drive to get computers and their personal components to be faster and faster.  A common joke among techies was not to stress when buying a new machine that you get all the latest and greatest.  “As soon as you buy it, it is 6 months out of date.”  This statement illustrates the speed in which the technology was being enhanced, continually getting faster and more powerful.  One of the barriers was getting speed of a home computer up to and past 1GHz (Gigahertz).  A Gigahertz is 1 billion cycles per second.  The goal was to have computers processing at least 200 times faster.  Okay, we know that the two trends listed at the beginning of the article happened, and continued to happen, so why was there a “barrier”?

The problem has to do with the following electrical formula:

W = V x I

This formula, derived from Ohm’s law, is the electrical formula for power.  W = Wattage, or how many watts are generated.  V = Voltage, the “potential” for an electric circuit.  I = Current, measured in amperes (amps).  It is the amount of electricity being carried.

Okay, Mr. Science, thanks for the lesson.  But what does it mean?  We need to relate this to our frequency measurement, Hertz.  As the Hertz increases, the clock pulse increases, and the amount of information that is carried increases also.  That information is carried as electricity.  So, when the frequency increases, so does the current in the system.

Okay, so more electricity is being generated.  That’s a good thing, right?  Well, yes.  But look at the formula again.  Wattage is the unit of measure for power.  In this case, that power can take the form of heat.  This is what caused the barrier.  During the “race to a Gigahertz” multiple CPU manufacturers were working diligently to get a CPU that could run at and beyond that speed.  Problem is, when cycling up the circuit to that speed, the CPUs would run way too hot (you could fry and egg on them).  Remember from basic science that heat causes expansion as molecules move away from each other.  Heat, of course, would cause expansion of the silicon and the circuits, causing failure. 

The solution of this was to change the structure of the CPU to incorporate other metals that run cooler, such as copper. This technology was not actually invented by Intel, AMD, or Motorola, the CPU manufacturers for PCs and Macintosh computers.  It was invented by the Digital Equipment Corporation.

You may be aware that nowadays there are solutions for dissipating heat.  These come in the form of cooling fans and heat syncs.  Heat, however, still can be a problem if you do not care for your system properly.  And this is not just the case of PCs.

All electronics nowadays have powerful processers that run at higher and higher frequencies.  This is what allows us to have more complex appliances and devices.  So not only can your computer have a heat problem, but other electronics can as well.  Electronics manufacturers work on the heat problem in different ways – computers have cooling fans and heat syncs, televisions and video games have these as well as ventilation, even a smart phone has a heat sync.

The measures that manufacturers take do not always work well.  Some electronics overheat if they run too long.  I myself had a video game system that ran so hot it would “crash” within minutes of turning it on.  This is because the heat was so high that the system’s memory would expand and pop out of the circuit board.

So you are probably asking yourself, “What can I do?”  

I wouldn’t expect you to modify your electronics to better cool them.  (Although many a gaming enthusiast has added liquid cooling to their computers and gaming systems, this is advanced tweaking best left to an expert and can void a warranty.)  The key item for the average person to focus on is ventilation.  Most larger electronics have fans to dissipate heat.  If the casing of the system isn’t ventilated properly, the heat becomes trapped.

So, your tips for this week are:

·         Do not stack electronics on top of each other without adequate spacing between.  (Some electronics are made to be stacked, this is as their ventilation is to the sides, not top and bottom.  When in doubt, look for the vents or feel for the air flow when powered on.)

·         Don’t pile things against or encase your electronics to close to a shelf backing or wall.  (Again, keep the vents clear.  Leave a few inches at least to the sides of a shelf or wall.  The key is to keep adequate space around your electronics.)

·         Check vents periodically for dust.  Use an air can to blow away dust (available wherever electronics are sold).

·         Shut the system off once in a while!  (Video game systems will run hot after hours of gaming.  Encourage the kids to take a break and go play outside or read a book.  Feel the casing, it will probably be warm.  If it is getting too hot, time to save and shut down.)

·         Keep your systems at room temperature.  Again, basic science.  I’ve known people to keep their video games in their garage or unfinished basement (read “man cave).  In the extremes of summer and winter, keeping electronics in areas without temperature control will cause them to fail.  (Remember, cold can be an issue as well.)  This also goes for leaving electronics in a car – I know more than one person who left a laptop in a car overnight, only to come out and find the screen is ruined.

Hope you enjoyed this article's tip.  Thanks for reading!