Laptop Next

Laptops are now a full-fledged replacement to desktops and have come a long way for this. However, one shortcoming and area where no improvement could be made is the battery life: new laptops, today in the market still get just 2-4 hours of battery life i.e. no better than they did 4-5 years ago. According to IBM employees, they are still trying to get longer battery life with the help of lower power CPUs, technology involved with battery and many more but no such improvement have come out yet. Intel, the chipmaker moved up the deadline recently for notebook makers by two years and asked them to produce light and thin notebooks capable of running for eight hours without the use of external batteries.

Sadly enough, no one is close to such statistics but deadline is upon every notebook maker. To answer the question as what exactly is eating up laptop’s battery life, Kill-a-watt which can measure power devices’ consumption of power was used and comparisons from some other laptops were used and notion of undervolt and its affect on power consumption was noted.

Undervolting and Underclocking are used to lower the clockspeed and/or voltage to achieve lower power consumption. As overclocking can result in an unstable system, there is trial and error method involved with it. Laptop processors run at a lower clockspeed which allows them to run at lesser voltage; the laptop can throttle down to lower speed of clock and then ramps up when it is needed. The result of comparison between several laptops at ideal conditions showed that reducing the brightness of the screen can significantly save 20% of battery whereas converting to solid state drive from normal hard drive can only save an extra 5-10% over conventional drives which are under heavy usage. Hence for just gain of 5%, rationalization for extra $1000 is not a good idea; money can rather be invested in second battery instead. If CPU is throttled (so that processor never goes to higher rated speed), there can be large drop in power consumption. The power savings can be between 15-40% at higher usage. One disadvantage, however, is that if CPU is throttled , some of the productivity can be lost as computer takes longer for performing high CPU calculations.

If you run a processor-intensive application in case of Centrino, which involves 100% usage of CPU, it would take 30% less power but would roughly take twice as long to run, so throttling CPU does not always make sense if you are undervolting. When undervolting is not involved, there is 40% less power but 48% more processing time is required making the whole thing pretty wash. The other thing to note is that as most mobile use does not require heavy CPU processes, running at throttled speed is more beneficial for those who mostly browse the web and watch videos.