The easiest way to cool down your ultrabook (or any laptop, really)

Right now it’s summer in Australia, and my ultrabook PC is getting hot quickly, which is annoying when I’m holding it on my lap. I own an Asus Zenbook (the UX360UAK to be specific), which houses the powerful Intel i7–7500U. This is a powerful processor, with an integrated graphics processor that allows me to do pretty much anything from working in Python to play Skyrim at 40fps. However, some applications tend to boost the speed of the processor, making it run hotter and louder than I would like.

I have spent hours researching for a way to cool it down and found basically 3 methods:

1. Use a cooling pad
2. Undervolting, with programs such as ThrottleStop
3. Cap the maximum power in the windows power settings

While cooling pads are efficient, they are not practical for the on-the-go possibilities of an ultrabook. I use one at home, but not when I work at a café or a park. Undervolting, on the other hand, works by making your PC work with a lower voltage than the default, saving energy and reducing heat. Getting it to work, however, is an advanced procedure and requires some testing to avoid crashes.

So what can the non-advanced or short on time ultrabook owners do to reduce the heat? You can tweak the windows power settings, reducing the maximum performance of your CPU. It’s not perfect, but it gets the job done. It makes your PC a bit slower sometimes, but saves battery and reduces the heat.

I have made a quick test to test the effect of this approach. I had 5 tabs open simultaneously in Firefox, 4 of the tabs running Python Jupyter notebooks and one with Youtube, on Windows 10. The charger was connected during the test.

In the first 5 minutes, when set to high-performance mode, I registered temperatures between 50ºC and 55ºC (122ºF and 131ºF) and sometimes 70ºC (158ºF)! In the following 5 minutes, with the ultra power-saving mode, the temperature slowly stabilised below 45ºC (113ºF). The difference was a reduction of 7ºC in average! Check the graph below for yourself.

10-minute test of the differences when changing windows power options. The temperature and power were measured every 5 seconds (each red bar = 5 second interval). Data logged with Open Hardware monitor.

The chart shows how in high performance mode the CPU can jump quickly to 70ºC when the power consumption goes up for some task. The temperature takes a bit longer to reduce down even after the power consumption goes down — which means that it’s these spikes in CPU usage that makes your hands feel like the PC is burning while you type. Using windows power management approach, I get the best temperature and battery life from my ultrabook.

Does it feel slow and sluggish? Browsing is mostly unaffected. Opening programs takes about one second longer than usual. Naturally, this mode is not made for CPU intensive applications (e.g. gaming, video editing), but it will do wonders with standard MS Office work or browsing.

Guide to get the ultra power-saving mode on your PC (with pictures):

1. Open the windows settings (type settings in the start menu). For Win7 or lower, look for the power option is in the control panel.
2. In the search box write power plan and select the Choose a power plan.

2. In the new window that appears, select Create a power plan.

3. Create your new plan based on the power saver plan, and choose a name for your plan (like Ultra power-saver). Once it’s done, press Next.

4. In the next menu, you can select your display and brightness settings. You can chose what you like or just press create.

5. Now your plan should appear in the list. Press Change plan settings.

6. In the next window, press Change advanced settings and find the line with Processor power management. Change the values for maximum processor state to 50% so that the processor can run only at half of its capacity.

You can choose to change the numbers to something that works best for you, but the values in the picture below have been working well for me for the last month. And whenever I feel that the computer is getting too slow, I can change it temporarily to balanced or high performance, knowing that this will warm up my hands.

I expect this to work well in most i7 processors and i5 for any recent laptop. Less powerful processors might feel too slow when the performance is capped at 50% — in that case, try with higher values.

Does this method work for you? Let me know your feedback in the comments below!