New at this and fan speeds limited


New Member
This has probably been discussed in here, but my search isn't finding it (I suspect I don't know enough to ask the right question).

Alienware 17R3.

I installed HWINFO64 a week or so ago. It was, I suspect, an older version. But, I figured out a couple sensors and got it to work. For the CPU I was able to specify fan speeds at different temperatures, so it went from 1000 rpm to 5000 as the temps went up. This morning, it updated to the current version, which appears to be 6.1.2. When I went in to check the fan speeds it told me I could ONLY use 0, 2500 and 5200.

The CPU sensor I'm using is ACPI: Alienware 17R3, and it says it's "CPU"
There's another sensor named Alienware 0GH72M (Intel PCH) that says its "PCH Temperature"
And a third that says DELL EC: Alienware 17R3 that has both CPU and GPU

Is there a preference for which one (or ones) I use?
Should I turn OFF the EC Support on this laptop? Currently it's OFF.

Is there anything else I should know as I go forward?
This has been indeed answered several times on this forum.
Using the EC=OFF option offers only those limited speed levels, which is a BIOS limitation. Enabling EC Support should allow more detailed levels (with steps of 100 RPM), but this mode can cause issues on some systems especially when the battery is installed in the laptop (due to conflicts between fan control and battery monitoring). Some users solved this by removing the battery. Unfortunately there's no 100% safe and versatile method possible.
As for the temperature source, you should also see a CPU dedicated sensor (DTS), which should be most reliable.
Thanks for the info...
When you say it can cause issues on "some" systems, does this mean some 17R3 systems or does it mean some of the several Alienware systems?
Is the CPU dedicated sensor the one labeled "ACPI: Alienware 17R3"?

I"ll try seasrching for anything "Alienware" to see if that turns up a match for my 17R3...
Issues can happen on any Alienware notebook.
No, I meant a different CPU sensor.
I turned EC Support back on. So far no problems. I only find 2 CPU sensors, so I went with the ACPI one.

I ramped the fan speeds up pretty linearly 'til 70C. Then I set them both to 7000, which appears to be the maximum speed, and also the point at which the thing sounds like a jet engine.