Linux Community Magazine

We can some mathematical know, how many additional battery life can you, for example, you can the platter to reduce the speed of the hard disk. Currently on the market of a typical notebook has about a 50-100 Watts of power, this is a very good 2-4 hours capacity lithium ion battery. Suppose we have a 50-watt battery laptop. If the battery for 3.5 hours continuous operation then we can hard drive, as 50/3.5 = 14.3 watt average power consumption charge. Said laptop notebooks with a typical hard drive, it uses about 0.9 Watts in standby mode about 0.3 Watts in standby mode. In theory, we can reduce the power consumption 0,6 Watt and reached approximately 13.7. This increases the battery life 50/13.7 = 3 hours and 39 minutes. Profits you always depends how much electricity you save total electricity consumption. In our example below rotate about save overall performance, 4% so that the battery life for maximum gain of 4% as well.Laptops give to do you the freedom you want to do wherever you want. But all these are, how long you can laptop battery decided last. Lucky is that it many ways energy to save longer battery life. For example, can reduce the speed of the processor and the brightness of the backlight and disk spin-down. The first two Linux knowledge, but until recently, can be a considerable decline in the fight by turning the hard disk. Even if you get when driven rotation, it is never long enough to save any of the powers. This article describes how use the notebook mode, a function, which recently to the Linux kernel, the actual spin. Linux2.2.1. I said only a laptop computer model 6 in 2.4, but it is a bit different.Laptop mode is a Linux kernel and the kernel in the course of time is how the distribution of disk I / O settings to change. Linux disk I / O for a small amount of normal, well distributed in a timeout. But all I / O's, your hard disk has to an opportunity never slow given waste of valuable energy. For a notebook, the acti vity of the hard disk in a very short time to concentrate, and the latency between them, like me, like the baseline should. If you allow laptops, Linux makes. You can set up is to get extended ten minutes it no activity of the hard drive it is certainly to improve the battery life of laptops.You use it on the laptop mode you can as many as a dozen minutes is it set no activity of the hard disk. If you do not change to any file, you can rotate the disc, or even a long time. After all, if there is nothing to write, there no reason the disk turns. It is unfortunate if you use the default option installs the file is, change time, access to the file system. Access time updates, even if you read only the files that must be written it on the hard disk after all. To avoid this problem, back, all file systems use laptop mode the unique mount option. This makes them the recording to stop time, so you can actually not ten minutes more than disk-I / O?I would so many theories, like to t ell you some real data. I borrowed a friends Dell Inspiron mini 10, installation Debi and GNU / Linux and Linux 2.6.6 kernel, and then a little experiment. I think battery life estimates the maximum gain and time, between spinals close to the maximum extent need. I expect a considerable gain, and maintenance of the system because laptops with 5400 U / min hard drive power consumption are equipped, because I denied all x servers. I wrote a benchmark, always the same amount of I / O plate per hour, but invalid and configuration I / O between periods. The inactive time, hard drive spin down the benchmark program. I ran a cycle length document number, and I use the APM battery to charge information about the expected Dell Inspiron mini 10 battery life.