Some people love fan noise, using it to help get to sleep or just create some ambience in a room. Others hate it, like [Dimitris], and will take severe measures to eliminate it where possible. When his Razer Blade laptop was incessantly whirring away, it was time to get to work.
The Razer laptop uses a controller that outputs a variable duty cycle signal to control fan speed. Unfortunately, the fans never fully switch off, even when the laptop is cold, leading to frustrating excessive noise. [Dimitris] implemented an ATtiny85 to intercept this signal, giving him full control over the fans. Two modes are implemented, one which keeps the fans off when the duty cycle is at its minimum, and the other that attempts to keep the fans at a minimum speed wherever possible.
While modifying the critical cooling system of a high-performance laptop is a risky business, it’s a decent price to pay for some peace and quiet. We’ve seen quite the opposite to this mod, too – like this Xbox 360 outfitted with additional cooling.
Razer at least fixed this problem in the 2017 models, I have one, the fans shut off and the machine spends a lot of time churning away silently, until you load it up of course.
Instead I’m just sad that they didn’t bother with type c charging even though other models in range have it and competing models of similar spec do.
Nice. Only thing to keep in mind that those fans not only cool the cpu/gpu but the rest of the system too.
If I disable the fans in my machine the CPU stays at ~50 C during browsing the net, etc but the temperature of other components starts to rise. SSD reaches 70oC after 15-20 minutes, the underside of the laptop becomes quite warm, especially around the RAM and the dcdc converters which supply the CPU. Solution is to switch on the fan for half a minute in every 10 minutes or so.
Here is a tool that supports changing the fan curve for a number of machines: https://github.com/hirschmann/nbfc
Even if yours is not on the list, search for one which is “close enough” and experiment with the config file. That’s how I got mine working.
If the bottom of the case is metal, add thermal pads to the hot spots.
true – I used to have an app that modded my fan behaviour for a Dell laptop. It kept my laptop far more silent, but it degraded my Li-ion battery pack more quickly; 2 of the 6 cells which were located directly under the CPU where the culprit.
Nice work! I also hope the other components are not getting too hot while on low load. Thank you for this article!
Btw: I think this name is Dimitris not Dimitri.
Thanks, fixed!
“Unfortunately, the fans never fully switch off, even when the laptop is cold” For my laptop this is a feature… a controllable one, since I can choose to keep the fans running slow when it is plugged in, but they always turn all the way off if on battery. This keeps the laptop cooler and extends the life of the components. Mine is silent enough that I can barely hear it in a quiet room.
2020 is coming whereas fanless laptops are not:)
My bad should have said: performance laptop. I just refresh my knowledge and all I was looking for when buying laptop is now on market. Its like with this box of junk you call “spares” – as soon as you throw it away you need those parts.
Be careful with the setpoint deadzone and thermal sensor gain. I’ve seen a production commercial RF amplifier designed with too high of deadzone that waited until the PA stack rose in temperature before turning on (too much) fans which cooled it down and shut off the fans. After about 6 months a high percentage of the amplifiers failed due to thermal stress fractures of solder joints on the power components that had a considerably higher temperature than the heatsink where the thermal sensor (and thermal mass) was. As the fans constantly oscillated on and off the connection joints would flex on the circuit boards and eventually crack. The mfgr fixed this by leaving the fans on (100% cure) but there are better ways of fan control to eliminate this problem by adjustment if the deadline and sensor and cooling “gain”.