What About Fan Controls?
To reduce fan noise, the Power Options utility can be used to manage fan behavior. When the Adaptive mode power scheme is active, it's possible to limit maximum fan speed to any of five speed settings.
The CPU-Fan-control option limits fan speeds to five discrete settings.
Those who select Option Level 1 (quiet) will quickly see that this restricts the fan to so slow a speed that it can't even adequately ventilate the case when the CPU is running at 600 MHz (half its maximum rated speed, and normal when running off battery). To keep the laptop as quiet as possible and to protect the CPU from overheating, the device also slows down the front side bus from its usual 100 MHz to 40 MHz, thereby also slowing the CPU clock rate to 240 MHz.
The Sony Vaio VGN-TX1XP can slow the CPU clock to 240 MHz.
At this low CPU clock rate, it's not possible to do any meaningful work, but the laptop does run somewhat more quietly. Thus, Option Level 1 (quiet) only makes sense when you want to read an e-book on the laptop in relative peace and quiet, or perform other tasks requiring very little computing power. But even reading a text file while also surfing the Web isn't feasible at this lowest of all possible CPU clock rates for the Sony.
A Networked Power Saving Concept
As we mentioned in the introduction, it's possible to realize battery lifetimes of over seven hours from a single charge of the standard battery for laptops in Sony's TX series. But to make this artful dodge possible, Sony's engineers had to expend lots of effort and brainpower on the power saving mechanisms in this laptop's individual components. Only the combination of these individual mechanisms into a power saving scheme for the entire laptop could enable what might initially appear to be a fanciful claim about the unit's battery lifetime. On the pages that follow, however, we'll explore the particulars that make these individual power saving mechanisms work.