Undervolt your Laptop!

Squeeze a little more battery life from your laptop and reduce heat this summer!

Enthusiasts tend to overclock their gear to unlock its hidden performance potential. Unfortunately, this opportunity is rare, or very difficult, when it comes to laptops and netbooks - particularly with the CPU side of things.

Netbooks tend to attract more attention, such as the ASUS Eee, so there are cases where overclocking may be fairly simple. There are also gaming notebooks which have overclocking features inbuilt. But what about all those people who don’t have this opportunity? And even if we do, is the reduced battery life and extra power usage worth the trouble? Luckily there is another – just as awesome – way to tweak our precious hardware. Undervolting, of course!

Now you might be thinking, ‘Undervolting?! Why the heck would you do that?’ If the sub heading didn’t give it away, it’s to reduce the extra power usage that the CPU really doesn’t need. Most would be familiar with the great overclockability (is that even a word?) of the Intel Core 2 architecture, even on stock voltage. This is what makes undervolting so viable, the stock voltage is often much higher than it needs to be for error free processing. If it hasn’t become clear yet, the obvious step is to lower this voltage, and this is how!

Download a copy of the freeware application RMClock. This software has a vast range of uses apart from undervolting, such as multiplier adjustment, CPU/OS load level monitoring, power management, and many other low level goodies to play with. For the moment, install and run the program.

You’ll be greeted with a small window with a list of ‘pages’ for different settings, as shown below.


We’ll start off with the ‘Profiles’ page which houses all the P-state (i.e. performance profiles) for your CPU. If you only want specific clock speeds to be used, untick the ones you don’t want. This will restrict throttling of the CPU to whatever you select. Since we’re undervolting, you could get away with only ticking the fastest ‘normal’ state in addition to IDA and SuperLFM. IDA stands for Intel Dynamic Acceleration, which increases the clock speed of one core while the other is idle. SuperLFM (Super Low Frequency Mode) allows for a much lower idle speed and voltage. This is especially good for saving power.

Now for the fun part! Next to the P-states you have ticked, lower the voltage by one increment. For the moment, only choose one state to lower. By doing this, stability testing becomes a whole lot easier. Once a stable limit is found, the others can be adjusted accordingly. The screenshot below shows a T8300 with custom states.


Click ‘Apply’ to confirm your settings. Nested under the ‘Profiles’ tree is four sub profiles. The first turns off any manual management, while the other three are up to your discretion. Let’s start with ‘Performance on demand’, click it to open its specific settings.