dstutzman is correct. After all, we all know computers have fans and that CPU's emit heat. We also, know that fans cool hot objects. The 910 is no expcetion. 

Furthermore, I use 4 different laptops at home & work (2 Surface Pro's, Del XPS, & Dell Inspiron) & none of them shows same 'fan' behavior the 910 does. I mean ...

1) The 910 fans, duing my use, are on 6 hours non-stop. Window's task manager shows CPU usage history not exceeding 10%. 

2) The buzzing & high pitch sound of the fan (mostly on left side) is distrubing. I'm unable to enjoy watching a movie or comfortably focus on a TedTalk. It is sad because the speakers on the 910 is the best out of all the laptops I have. 

I hope Lenovo support is monitoirng this forum to help facilitate in identifying the issue and fixing it. 

What i'm saying is that mine is not getting hot enough to warrant fans being on at the speed that they are spinning. I tend to get bouts of the fan going at very low CPU temperatures.

It sounds like there are different fan related issues

I think we can all agree though that the fans placed in these machines are noticeably whinnier than those in the new Macbook Pro's for instance

In terms of when the fan turns on, your mileage may vary of course, depending on many factors. In my testing, the fan revved up at temps over ~43 Celcius, and went full speed above 60 or so. 

After some benchmark testing, I can't really say I recommend the 99% CPU "fix".

Geekbench 4 scores, High Performance mode, on battery, 100% max CPU:

4217 Single-core

8010 Multi-core

99% max CPU:

3527 Single-core

6623 Multi-core

This is a pretty big hit to performance. This will be fine for most use cases, but if you need the extra power, you're going to have to deal with the fan noise. Lenovo may be able to tweak the fan curve a bit with a BIOS update but potentially at the cost of shortening the life of the CPU.

Hi, thank you for so much informantion on this problem. 

We are woking to have a bios update for the fan noise.

It's weird for us if the fan noise is noticable when the CPU temperature is under 50 Celsius

I'd like to talk with you to get more information, am I welcome for that?

how can I get to you? via some IM app?

Yes, 99% not only disable the CPU turbo but also limit the CPU TDP

Hi, thanks for paying attention to this problem. 

When I set the max CPU to 100%, it is very easy to kick off the fan to full speed, which is super loud and kind of embarassing in an quiet office or conference room. It seems that the fan speed is set to be reactive to CPU load instead of the actual temparature, because I believe it is more rear full-speed fan is absolutely necessary (for example, when setting to 99% the fan never hits full speed but the laptop is still cool.)

The other issue I am experiencing everyday is the fan would randomly kicks in super hard for several second and then stops, when I am not doing any remotely heavy work. It is fine but just wierd. 

You can contact me via messages on the forum and I'll send you my personal contact. Thanks again, this is a lovely laptop if not for this particular issue.

Due to customer reports of fans running with a noise volume that is louder than expected on Yoga 910-13IKB systems, Lenovo has launched an investigation.

It would help to know the following information from a minimum of three customers:

• Is this occurring on a Yoga 910 with a FHD IPS display or UHD IPS (4K) display?
• In the Event Log -> Windows Logs -> System are there any events being reported?
• Does changing Power Settings -> Power & Sleep -> Advanced Power Settings -> from Balanced to High Performance resolve the issue? Does changing the settings one more time to Balanced resolve the fan issue for the rest of session? After resuming from sleep? After a reboot?

One housekeeping note: the Forums team is in the process of verifying Melon as a Lenovo employee/vendor.

Thank you,

Is this occurring on a Yoga 910 with a FHD IPS display or UHD IPS (4K) display?

Both. I purchased both to compare. (Btw, the 4K display on a 14 inch laptop serves little purpose other than to drain battery -- there's virtually no perceptible difference when your eyes are more than a foot away from the display, at least to my eyes... However, the 1080p panel is significantly worse with colors, brightness, and contrast, so the 4K version is still the one to get)

In the Event Log -> Windows Logs -> System are there any events being reported?

Strangely, yes. There are thousands of them, anywhere from half a dozen to 50+ occuring each second.

The source is "WHEA-Logger", level "Warning", event ID 17.

"A corrected hardware error has occured.

Component: PCI Express Root Port

Error Source: Advanced Error Reporting (PCI Express)

Bus: Device:Function: 0x0:0x1C:0x0

Vendor ID: Device ID: 0x8086:0x9D14

Class Code: 0x30400"

Does changing Power Settings -> Power & Sleep -> Advanced Power Settings -> from Balanced to High Performance resolve the issue? Does changing the settings one more time to Balanced resolve the fan issue for the rest of session? After resuming from sleep? After a reboot?

Not really, no. As far as I can tell, everything is working exactly as intended. This is a high-end mobile processor and it needs to be kept cool, and the only way to do this is with proper cooling design (i.e., a heatsink, a fan, and so on). Customers can't reasonably expect the fan to never come on when the processor is being utilized, and though browsing the web may seem like a low-power activity, the system will use the resources it has in order to keep things running quickly and smoothly. The fan itself is the problem, in my opinion, not the system or CPU or even the cooling design. The fan is just tiny and noisy and there isn't much that can be done about this.

The Forums team is in the process of verifying Melon as a Lenovo employee/vendor.

Thank you, I was curious about this.