How to enable automatic fan control

[subodim]

I have two different machines that are virtually identical. I have the same problem with both of them, so I feel that there is unlikely to be an identical hardware failure in both of them. The case fans and CPU cooling fans are original equipment and they are capable of operating at variable speed when connected to a 4-pin PWM connector. The BIOS setup program for the latest L02 BIOS dated 4/19/19 offers limited options for thermal control. Under the "Power" options tab, there is an option called "Thermal" which allows you to set the minimum idle speed of the fans. HP documentation states that this option only controls the minimum idle speed of the fan, and the fan speeds are "automatically controlled". I don't know how the machines accomplish automatic control, but there is no option to change any settings related to that.

I installed Windows 8.1 Pro with the original HP disks, using the embedded Windows 8.1 product keys. The case fan and CPU cooling fan always run at idle speed, depending on the speed I set for them under the "Thermal Option" in the BIOS. A low fixed speed is suitable for most applications, but under full load (as tested with Prime95), the CPU temperature can exceeed 75 degrees C. If I set the idle fan speed to maximum, the CPU stays at a temperature of less than 60 degrees C even under full load but the noise is unacceptable. Clearly, the fans are not defective (and they are very clean). The problem is, the automatic fan control is not working.

I've used third party programs such as HWMonitor to check the core temperatures, but I haven't found any program that is able to report fan speeds. (HWMonitor reports fan speeds as long as it can read them from the system.) Third party programs such as SpeedControl don't work because the fan speeds cannot be read from the system.

Is there a proprietary HP driver required to make the automatic fan control function properly? I've read other reports in this forum from other users who have experienced the same problem but I haven't seen an effective solution. I haven't installed an unsupported operating system and my fans are not defective.It seems unlikely that the PWM thermal chip has failed in both of my motherboards at the same time. I noticed that they stopped working some time after I installed the latest BIOS, which updates the CPU micro code to fix the Meltdown security flaw. An older version of the BIOS cannot be installed.

Thank you for any assistance you can provide.

[DGroves]

when in a bios submenu (like the fan setting) you must press the  F10 key (as i recall for your model) to actually store any changes before leaving that page and then select "SAVE changes" to actually make the changes permanent

in other words, entering a bios sub page, making a change and then exiting that page will cause any changes not to be stored, they will default back to bios defaults

[subodim]

Thank you for your reply.

I have set the minimum fan speed to three different levels (and saved the changes when exiting the setup utility). The CPU temperature exceeds 75 degrees C at low speed and medium speed under full load. The noise level is unacceptable at high speed. Making changes to the minimum fan speed (the only option available in the BIOS) does not enable the automatic fan control. Do you know a way to do that? That's the problem I'm trying to solve.

[DGroves]

first a few questions

how are you arriving at the 75c temp?, which program is being used? is the program measuring CPU TCase or TJunction?

what load is being put on the system? (ie-software running)

has anyone messed with the systems heatsink? and if so what was done? (IE- was new thermal paste applied)

keep in mind that small cases by nature will run hotter than a larger full sized case

[subodim]

Thank you for your reply.

I'm using HWMonitor to see the temperatures of the cores. I don't think HWMonitor measures the TCase or TJunction; it tells you what the internal thermal monitor in each core is reporting. It also tells you the temperature of the "Package", which may or may not be the same thing as TCase.

I'm using Prime95 to put a full load on the processor. When the processor is idle, the core temperatures are around 40 degrees C.  The CPU power consumption is around 4 Watts according to HWMonitor. Under full load, the CPU power consumption is around 66 Watts.

I purchased these two computers in used condition about three years ago and I began refurbishing them at that time. I cleaned them thoroughly. I upgraded one of the processors (originally an i3-4330) to an i5-4570. I removed the fans from the heatslnks to clean them and then reassembled them. When I re-installed them, I used Arctic Silver 5 thermal compound.

I don't recall having any problems with the automatic fan speed control when these machines were running Windows 7. I wasn't using them for the last year or so. I recently decided to add 240GB SSDs to run as boot drives and upgrade to Radeon RX 550 video cards, which I haven't installed yet. I installed Windows 8.1 Pro on the new SSDs using the original HP installation media and the embedded Windows 8 product keys. That's when I noticed that the case fans and CPU fans never change speed. They always run at the minimum speed they're set to in the BIOS (the "Thernal" option under the "Power"tab). I'm guessing that the slowest speed is around 500 rpm and the highest speed is close to 3000 rpm.

What I really want to figure out is how to make the automatic fan control work. I installed Intel chipset drivers and Intel Management Engine drivers. I don't see any unidentified hardware in Device Manager. I can't tell if any drivers are missing.

[DGroves]

hwmonitor like most apps of this nature is not accurate in reading the actual temperatures as the actual algorithm  used to read the cpu temp is only known by the chip maker using the bios to read the cpu temp is considered by most people to be more accurate hwmonitor however is  quite able to show the difference between low/high temps accurately 

next prime95, is not a real world application as no software currently made will stress a cpu like prime95.

in a nutshell you are never going to see the same temp's running real software i recommend you read the prime95 documentation which does mention this fact it's normal for a system cpu to get hot during prime95 and this does not indicate a issue with system cooling

the cpu fan speed is on a seperate thermal sensor from the ambient (case fan sensor) when in the bios changing the fan speed will only affect the case fan(s) not the cpu fan speed for HP workstations

the case fans on a hp workstation cold start should ramp up in speed and then ramp down during the startup

i would make sure the fans are connected to the correct fan headers and on the correct pins.... as some hp workstation cpu fan headers have 5 pins, (not 4) as the fifth pin is used as a detect to tell the system a high performance heatsink/fan is installed  if you replaced the HP fans with aftermarket ones (not recommended) they do not have the proper fan header,

as the hp cpu fan connector is 5 pins (5 pin header is not connected on low power heatsink/fan) 

[subodim]

I'm using the original CPU cooler and the original case fan. The CPU fan header is a standard 4-pin PWM header, and the case fan header is a proprietary 4-pin header. I don't think you could connect a standard 3-pin or 4-pin connector to it because of its shape.

It doesn't really matter what the actual temperatures are. Under normal operating conditions, the fans should run at a low speed when the system is idle, and the fan speed should be much higher when the system is under load since there is a marked temperature increase. The automatic fan control is not working, so the fans run at a constant speed (the minimum speed) no matter what the temperatures are.