| Model | Power @ 25% | Power @ 50% | Power @75 % | Power @ 100% | ||
| MacBook Pro (mid-2012, 15 inch w/ Retina Display | ||||||
| Volts | 117 | 116.6 | 116.8 | 117.2 | ||
| Amps | 0.542 | 0.546 | 0.564 | 0.603 | ||
| Watts | 11.2 | 12.2 | 14.4 | 18.5 | ||
| Apple MacBook Pro (13-inch, mid-2012) | *Could this computer be affected by viruses?* | |||||
| Volts | 118.8 | 119 | 119.1 | 119.4 | ||
| Amps | 0.908 | 0.923 | 0.936 | 0.961 | ||
| Watts | 44.3 | 44.6 | 45.9 | 48.3 | ||
| Apple MacBook Pro (13-inch, mid 2009) | ||||||
| Volts | 119.3 | 119.1 | 119.2 | 119 | ||
| Amps | 0.54 | 0.544 | 0.555 | 0.582 | ||
| Watts | 10 | 10.9 | 11.9 | 14.4 | ||
| MacBook Air (mid 2012, 13-inch) | ||||||
| Volts | 117.3 | 117.3 | 117.1 | 116.9 | ||
| Amps | 0 | 0 | 0 | 0 | ||
| Watts | 0 | 0.1 | 0.1 | 0 | ||
| MacBook Pro (mid 2012, 15-inch) | ||||||
| Volts | 116.9 | 116.9 | 116.9 | 117.2 | ||
| Amps | 0 | 0 | 0 | 0 | ||
| Watts | 0.1 | 0 | 0 | 0 | ||
| MacBook Pro (mid 2012, 15 inch) | ||||||
| Volts | 117 | 117.1 | 117.2 | 0 | ||
| Amps | 0 | 0 | 0 | 0 | ||
| Watts | 0.1 | 0.1 | 0 | 0 | ||
| MacBook Pro (2010, 13-inch) | ||||||
| Volts | 115.8 | 115.9 | 116 | 116 | ||
| Amps | 0 | 0 | 0 | 0 | ||
| Watts | 0 | 0 | 0.1 | 0 | ||
| MacBook Pro (mid-2012, 13-inch) | ||||||
| Volts | 115 | 115 | 115.3 | 115.2 | ||
| Amps | 0 | 0 | 0 | 0 | ||
| Watts | 0 | 0 | 0 | 0 | ||
| MacBook Pro w/retina (mid-2012, 13-inch) | ||||||
| Volts | 115.3 | 115.4 | 115.4 | 115.4 | ||
| Amps | 0 | 0 | 0 | 0 | ||
| Watts | 0 | 0.1 | 0 | 0.1 | ||
| MacBook Pro (late 2011, 13-inch) | ||||||
| Volts | 115.4 | 115.4 | 115.3 | 115.4 | ||
| Amps | 0 | 0 | 0 | 0 | ||
| Watts | 0 | 0 | 0.1 | 0 | ||
| MacBook Pro (13-inch, summer 2012) | ||||||
| Volts | 115.4 | 116.6 | 116.2 | 115.6 | ||
| Amps | 0.556 | 0.578 | 0.582 | 0.587 | ||
| Watts | 8.8 | 9.8 | 9.4 | 12.5 | ||
| MacBook (summer 2008, 13-inch) | *Molly’s Computer Exhibits Very High Power Usage. She may want to check for viruses.* | |||||
| Volts | 115.6 | 115.5 | 115.6 | 115.7 | ||
| Amps | 0.641 | 0.655 | 0.668 | 0.685 | ||
| Watts | 44.4 | 46.6 | 47.1 | 55.3 | ||
| MacBook Air (summer 2012,13-inch) | *High Power Usage* | |||||
| Volts | 116 | 115.9 | 115.9 | 115.7 | ||
| Amps | 0.43 | 0.733 | 0.739 | 0.745 | ||
| Watts | 32 | 51.6 | 52.2 | 52.7 | ||
| MacBook Air (summer 2012, 13-inch) | ||||||
| Volts | 115.6 | 115.7 | 115.6 | 115.7 | ||
| Amps | 0.373 | 0.368 | 0.337 | 0.384 | ||
| Watts | 24.6 | 26.6 | 26.6 | 28.3 | ||
| MacBook Air (mid 2011, 11-inch) | ||||||
| Volts | 116.7 | 116.6 | 116.7 | 116.9 | ||
| Amps | 0.536 | 0.543 | 0.549 | 0.561 | ||
| Watts | 9.9 | 10.7 | 11.2 | 12.9 | ||
| Every Laptop that we tested is some variation of Apple’s MacBook Pro or MacBook Air. Since Apple does not have specific “model numbers” for their laptops, we indicated the time that the laptop was released and the size of the screen. The data was taken using our Watt’s Up Pro’s supplied by Prof. Magnes. Electrical power is measured in wattage, which is equal to the voltage (volts) multiplied by the current (amperes). Amps are equal to the amount of electrical charge passing through a circuit per unit of time, with 6.241x 10^18 electrons per second being equal to one ampere. We measured the watts, amperes, and volts of each laptop with screen brightness at 100%, 75%, 50%, and 25%. Each laptop had every application closed except for Safari’s homepage, which was what was on the display for every measurement. There are some glitches in the current data. Tori’s Watt’s Up Pro gave measurements of approximately 0 for both amps and watts for a reason that is still under investigation. It is possible that the device was not configured correctly for reading current, as power = voltage x current, and a zero value for current would cause a calculated wattage to be zero as well. Some laptops, including Molly’s 2008 MacBook and the 13-inch mid 2012 MacBook Pro gave very high readings for watts and amps. We are considering possibilities for this outlying data, including the chance that viruses are causing the computers to run less efficiently or dysfunctional batteries. We will graph the data for each type of laptop, but it is clear from our data tables that increasing brightness consistently increases power usage. This is consistent with our original hypothesis. Amps also increase consistently, but voltage does not vary directly according to screen brightness. This makes sense since voltage is only the electric potential difference between two points.References:
December 2010 – By Steven S. Zumdahl, Susan A. Zumdahl – Brooks/Cole, CENGAGE Learning – 2010.12.17 – Hardback – 1,038 pages – ISBN 0840065329 |
Group 3 Project Data
Leave a reply