Most of the computing power you have in your office is wasted. Your computers just do not have enough to do to keep them busy even a tiny fraction of the time.
Most computer users do at least some word processing, but this example could apply to accounting, database, spreadsheet, and many other types of applications as well. Let’s assume that our user has a fairly typical computer system – a 33 MHz 80486 processor with 8 MB of RAM and a 500 MB hard drive – and that he or she is a pretty good typist – say 75 words per minute.
Note: This “typical computer” is becoming less and less typical every day as faster Pentium and Pentium Pro systems replace the slower 80486 systems. However I choose to continue using this system for my example, because faster computers waste even more CPU cycles and time. A nice, slow computer provides a good foundation for the rest of this proposition.
Let’s look more closely at a couple of things before we go further with this scenario. You have seen the specification before, for a 33 MHz 80486 processor in this system. But what exactly does that mean? This specification is a measure of the processing power of the brain of the computer. 80486 defines the type of Intel processor chip installed in the computer, and 33 MHz represents the number of clock cycles per second and defines how fast that chip runs. The 80486 computer chip is capable of processing one computer instruction every 4 to 7 clock cycles. Therefore, a 33 MHz 80486 – at 33,000,000 clock cycles per second – should be capable of executing approximately 6,000,000 instructions every second.
Our typist can type about 75 words per minute and it takes about 1500 processor instructions to process each keystroke. If we assume an average of 6 characters per word, we get 6 characters x 75 words per minute / 60 seconds per minute = 7.5 characters per second. And 7.5 characters per second x 1500 instructions per character = 11,250 instructions per second are used to type this document. That leaves 5,988,750 instructions available for use each second which have been wasted. Over 99.8% of the available processing power in this computer has been wasted because the computer simply sits there waiting for the user to press the next key. One way to increase the efficiency of our computer technology is to use those otherwise wasted clock cycles.
All of these wasted clock cycles are not the fault of your hardware, rather they are caused by the fact that DOS was designed in such a manner that it can only perform one task at a time. DOS was designed this way because the original IBM PC, back in 1981, was developed using some invalid assumptions. One of those assumptions was that the PC would be used in a single-tasking environment; that is, it would be turned on at the beginning of the day, run one program all day, and then it would be turned off at night. If the PC was on the desk of an accountant, it would run an accounting application all day long. If it were on the desk of a financial analyst, it would run a spreadsheet. If this PC were on the desk of a secretary, it would run a word processor all day long. There was no basis in these assumptions to provide a multitasking capability – that is the capability to run more than one program at a time.