I got a laugh out of this Penny Arcade comic today. Ah, the ridiculously hot laptop. We all know and love the scorching heat radiating from the bottom as we hen peck away on the couch. The timing of this strip was serendipitous for me as I’ve spent a couple of nights this week undervolting a laptop of mine, which is a term used to describe the process of lowering the voltage used to power your processor. Being massed produced, processors are usually set to be powered at a default, stable voltage level. However, at least in laptops, this level is usually overkill, hence the molting undercarriage.
I figured I would give undervolting a shot as I have a laptop that had different parts start failing on it, the battery, the built-in wireless, a machine not being used that is perfect for testing shit. The processor in it is a AMD Turion 64 running at 1.8 GHz. The default voltage was set to 1.075. Without the machine blue screening on me, I was able to lower the voltage to a stable 0.925 volts. The decrease in temperature of the processor was inline with the voltage drop, going from about 136 degrees Fahrenheit down to about 120 degrees when sitting idle. When running a stress test, the temp went from in the 180s to around 158 degrees.
The other cool thing about the software I was using, RMClock Utility, was that you could set it up for On Demand Performance. The processor could be set to run at a lower speed when the tasks running on the machine did not require top performance. This lowered the temperature to about 115 degrees when at rest, and writing a blog post on the machine did not require the full power to kick in. I set it up to run at the lowest, 800 Mhz being powered at 0.800 volts when power wasn’t needed.
The difference in temperature is definitely noticeable and well worth it in my opinion. However, I warn against doing it at the same time, as it seems kind of dangerous. You can plan on blue screening or having the machine just zonk out on you quite a few times before you find the lowest stable voltage. I have yet to try it on a machine that I actively use, and would certainly not attempt it without backing up my content first. Just be aware of the danger if you want to give it a shot. Here are some links that can guide you through the process if you are interested in giving undervolting a try:
I’ve been having some instability issues with the On Demand Performace function of RMClock. I found two stable voltages for 800 Mhz and 1.8 Ghz. When switching back and forth between the speeds though, the machine tends to BSoD after a while. Running at one or the other is perfectly stable. So now I just switch to the slower speed manually when performing a task that doesn’t benefit from top performance.
