I know that at least the Asus EeePC 1000H, HP DM1, HP 8440p, Acer Aspire 5315, and Acer Exensa 5620Z all insist turning on their CPU fan when the CPU hits ~50C or so.
The problem is that this commonly causes the fan to almost never turn off, particularly in the summer months, since it’s very rare to see the CPUs on these laptops ever get below 40C even after a repaste. Yet I’m not sure I’ve ever seen any of them hit above 70C despite being rated up into the 90C range, and the EeePC can even max out at around 80C with the fan turned off (and actually the DM1 can as well if you underclock and undervolt the CPU to around 70-60% of its stock performance).
The CPU isn’t the only thing in a laptop that needs cooling… The CPU/GPU cooling fans draw air into the case, cooling SOC,VRMs and other areas. Of all of the laptops I’ve ever had (9+), I’ve never seen a fan dedicated to cooling the latter components. I have added heatsinks to bridge/SOC chips and items not in contact with the heatpipes.
The CPU isn’t the only thing in a laptop that needs cooling… The CPU/GPU cooling fans draw air into the case, cooling SOC,VRMs and other areas.
And yet, the two laptops where this really bothers me, an HP DM1 and Asus EeePC 1000H, have both been running passively for literally a decade in average (since at least 2011 for the EeePC and since at least 2015 for the DM1).
Thing is, these are both very low-power laptops which is really where the question of overly-aggressive fan curves come in. Heck, because the E-350 in the DM1 is an SOC, that means the only other thing that requires cooling is the VRM, and that’s actually located on the exact same heatsink as the E-350 APU.
(to be clear, even though I’ve been running both passively, they both require software ran from the OS to achieve that - the EeePC requires it in order to set the fan speed while the DM1 requires it in order to underclock the APU to ~70% paired with a corresponding undervolt in order to be able to never go above 90c no matter what I’ve tried…except for hardware video decoding—that for whatever reason really heats up the APU, so I stick to software since the hardware decoder can’t do 1080p 60fps anyway, only 1080p 50fps and only h.264, but it can software decode h.264 720p 60fps anyway, so…).