Number 205 - June 2000

To Be or Not to Be ON - The Power Struggle
Reprinted from the October 1999 Journal of the Chicago Computer Society via Nov 1999 BECS Computing Notes
Some thoughts about that ongoing debate between leaving the computer always on vs. turning it off. Unless you're a full-time user of a laptop or notebook computer, running it solely from battery power, then this is an issue that involves your peace of mind as well as your dollar investment. You're allowed to choose sides: Is it better to keep the computer powered up at all times, or wiser to turn it off when you're not using it? Or, might there be other options to consider?     Back in ancient times, when DOS was the principle operating system, desktop computers used relatively small processing chips, weak in power but also loosely populated with transistors (as compared to today's crammed processors). In those days a hard drive was a clunky device that didn't operate so fast as contemporary marvels and held considerably less data than a Zip disk. But, because of such "inadequacies:' power problems were a much tamer concern, with emphasis directed more to protecting monitor screens from getting fixed images burned into the phosphor coating. Those among us who were considered forward thinking invested in jazzy screen-savers that featured flying toasters and likewise splurged on five-dollar surge protectors.     Fast-forward to the present and consider the vulnerabilities in the daily life of a computer. We now have sophisticated CPU chips with twenty times the processing speeds of less than ten years ago contained in an assembly scarcely twice the size of their predecessors. Miniaturization of that scale carries an enormous increase in heat generation. Similarly, higher levels of temperature build-up along with mechanical activity occur with the ultra-fast spinning of layers of platters in the new generation of hard drives. Factor in DVD or CD-ROM or tape devices and you've got a lot of action going on inside the case that houses your computer's operating system. Then, too, consider that almost everything is activated by standard on-off switches. Time to get involved. Defining the Consequences Is the First Step     So, what's the problem? Actually, there are several variations but basically two culprits, One deals with power surges (internal and external causes) and the other with dissipating heat. You can read a choice of viewpoints on these subjects with each one accompanied by technical proof favoring the author's stance. But the more reasonable recommendation is to review the salient points that follow and choose some course of action that's in line with your own risk tolerance.     Let's begin with a new purchase. The standard admonishment is to turn on the computer and its peripherals and keep them powered, day in and day out, for several weeks. Common wisdom is that defective products will fail during their initial use, so those that continue to perform after an extended trial are likely to deliver a useful service life. No argument there. But there's need to instill some caution here, nonetheless. Those on-off switches (CPU, monitor, CD/DVD-ROM) all need checking, too, and the one way to confirm they function as intended is to use them during the trial. For reasons that follow, it's advisable to schedule the "on" periods when you're at home. And, by chance, if the computer includes a power management feature, consider either disabling it or at least using the manual switches from time to time during the break-in period. (Such features perform power conservation by time-selected suspension or standby states for monitors and hard drives. The "soft off' operation is desirable but does not put user-operated switches to the test.) Arguments by the Always-On Advocates     Optimistically, assuming that a newly-installed computer has passed its survival trials, what now? If you heed the advice of one faction of experts, you forego the use of switches that control the on-off functions and limit the computer's "down time" either via internal power management commands (which put equipment in either a low-power or sleep mode) or, if that option is not present, simply leaving the system turned on. Reasoning for using an always-on mode is based on the effects of powering up a device from a totally-off state, creating a system shock.     Interestingly, an instant power surge going from off to on is not so potentially damaging as is the thermal shock. When components go from room temperature to operating temperature, around 175 degrees, the change occurs within 30 minutes at most. Similarly, turning off the system reduces temperatures at least as quickly. Since each component physically expands and contracts differently, the system must contend with unbalanced stress conditions. Everything from solder joints to adhesives can be affected, causing a variety of problems, such as intermittent contact failure and structural cracks. Now, the Views of the Opposition     Convinced that this is the way to co-exist with your computer? Everything that's been stated as to thermal shock problems will not be discounted. But there are	other factors to be reckoned with: overheating and energy costs, primarily. The first risk mainly involves the recent generation of computer chips, both for CPUs and video cards. As they've become more powerful, they've also become candidates for self-immolation. Not only are they dependent on heat sinks (the fins that surround a chip) to dissipate temperature build-up, but several designs--including Pentiums--utilize a miniature fan attached to the chip housing. That should tell you something about the need to control heat limits. So, what would happen if, inside your computer, that chip fan or the power supply case fan was to fail? The scenario is simple: overheating and probable damage. At heart, fans are basic mechanical devices, prone to wear out after "x" number of operating hours, most likely when the computer has been left on and you're away.     As for energy costs, these may be minor in comparison to your system purchase, but an always-on computer will make itself known on your monthly utility bill. Based on a local rate of $0.09 per kilowatt hour and a typical 1999 PC (350 watts for CPU, monitor, accessories), the cost for eight hours of daily use is around $88 per year or $33 for just three hours daily vs. $262 for never-off operation. For newer computers that incorporate components with efficient Energy Star circuitry, there would be a $50 yearly savings based on always-on usage. (Data from Que Corporation.) Do We Have a Winning Decision?     In a word, no. Based on the information presented, there are pluses and minuses for whichever philosophy you embrace. Most likely the extent of usage of your equipment will be the principal factor in making your choice. One school of thought recommends turning on the computer when you begin work, turn it off when you're through for the day, but not when you take any breaks. Regardless of your preference, there are several things you can and should do to improve the odds for keeping your computer healthy. Briefly, here's the menu:     (1) Select an Energy Star-compliant monitor if you are buying a new system or even replacing the display, assuming you are considering conventional CRT tube units. While there still is the matter of differences in temperature between operating and "sleep" modes, the danger quotient is far less than that created between on-off switching.     (2) Power surges and outages affecting your computer may be less hazardous to the health of your computer than the heating and cooling produced by on-off switching, but they can be responsible for transients that not only result in losing data but also contribute to cumulative chip deterioration. So, arm your system with at least a high-quality surge protector or preferably with a back-up power supply. Every surge protection device carries an energy rating in joules, a measurement that relates to power line spike tolerance. The higher the number, the better. Power back-up units for home systems are now relatively small and reasonably priced. Depending on their ratings and the type of equipment you're protecting, they can provide stable power for generally three to fifteen minutes as soon as an outage occurs adequate time to shut down your system properly (assuming you are present). Each model has wattage/voltage ratings and for an average home system look for no less than 200 watts; 400-500 watts preferable. American Power Conversion (APC and Tripp-Lite are two of the major vendors. Several of their models provide for CPU and monitor back-up plus surge protector connections for external peripherals (printers, scanners, speakers) and phone lines.     (3) Original-equipment cooling fans are cheap. Consider replacing the interior power supply fan with a heavy-duty, "whisper" unit or at least have a basic version on hand for a crisis situation. At many computer outlets you'll find these in the accessories aisle for under ten dollars. Likewise, get a spare heat sink-and-fan element for your processing chip (five or six dollars). Be wary of any esoteric cooling device such as a "slot" fan which replaces a slot panel at the rear of the computer case and gets power from the chain of internal power connectors. Unless there is provision for the fan to exhaust the air it moves, it will simply recirculate the warm air inside the case. And if you might be thinking that cooling could be augmented by leaving the case open, don't do it. What will occur is that the airflow from the power supply fan will be limited to that function with the rest of the breeze dissipating and the interior components relying solely on the benefits of heat sinks and ambient air convection. If anything, what you should strive for is a case that is sealed except for the required vents.     So, there we are. The always-on debate will continue, at least until technology provides needed solutions. In the meanwhile, if a computer has become part of the family, so to speak, then you shouldn't be surprised that, although it may be friendly, it's not without its weaknesses.
Number 205 - June 2000