[H81 TM-ITX] Downclock CPU

Kyjja wrote: Hello Here is my setup : H81 TM-ITX with BIOS 1.40 i3 4160 random sodimm Akasa Euler I want to underclock my CPU in order to run it cooler (passive heatsink-case) but I don't find the correct line in the BIOS options. User Manual haven't helped. Could you help me ? Thank you. Edit : Here are some photo of my BIOS. Note that the pics do not comply with the screen in the User Manual, which display more options for the CPU, including manual setting of the Frequency. http://i.imgur.com/mWgxyDy.jpg http://i.imgur.com/JaszzwY.jpg http://i.imgur.com/C9sb4OI.jpg

I see that the manual for your board, the H81TM-ITX, does not match the OC Tweaker screen picture you posted, as you said.

This is your OC Tweaker screen, correct? http://i.imgur.com/mWgxyDy.jpg

You would need to have in the OC Tweaker screen, the CPU Ratio option. That would let you set the core multipliers to underclock your processor.

Since that option is missing, you can set some other options to automatically downclock the CPU when it is idle and low CPU load situations. The CPU should go down to 800MHz most of the time with the options listed below set to Enabled.

Intel SpeedStep Technology

We can't see all of the OC Tweaker screen in the picture, but if you have these options, set them to Enabled:

CPU Integrated VR Faults

CPU Integrated VR Efficiency Mode

Power Saving Mode

In the Advanced, CPU Configuration screen, set all of these options to Enabled:

CPU C States Support

Enhanced Halt State (C1E)

CPU C3 State Support

CPU C6 State Support

CPU C7 State Support

Package C State Support

In Windows, be sure your Power Plan is set to Balanced or Power saver.

Did you ever have a BIOS version besides 1.40? I wonder if an earlier version had at least some of the options in the OC Tweaker screen shown in the manual.

I think the manual is wrong, most of the options shown in the OC Tweaker section really belong to a Z87 chipset board's BIOS, that allows over clocking (or under clocking.)

Your board's A-Tuning utility program that is run in Windows might allow you to underclock your processor.

Kyjja wrote: I have enabled these options, but they won't help me because i forgotten to say that I will use this computer as a calculation machine, meaning that the CPU will run at 100% 24 hours a day. By the way, I will run it under a Linux OS, so the ASRock Windows utilities can't be used. I don't remember if I had a previous BIOS version (before, I used this motherboard with an i7-4785T, which does not need to be underclocked to run at secure temperature). Is there a version which allow tu reduce the CPU ratio ?

I have no way to know if a different BIOS version had the CPU Ratio option.

When you installed the i3-4160 CPU, did you clear the BIOS with the jumper on the board before starting the PC again?

If you did not clear the BIOS with the new CPU, you really should do that. I don't know if that will change the BIOS options you will have, but should be done anyway.

The CPU Ratio option might not be displayed when using the i3-4160, because it does not have Turbo boost. The i7-4785T has Turbo boost.

The i3-4160 has a higher TDP (54 Watts) compared to the i7-4785T (35 Watts.) At 100% load, the i7-4785T will run at 2.2GHz, while the i3-4160 will run at 3.6GHz.

The stock, in box Intel CPU cooler is not designed to cool most Intel processors at 100% load constantly, or even for a few minutes.

The amount of cool air that is being put into the PC case with its fans will make a big difference with the CPU temperature, but using the Intel CPU cooler at 100% load on the CPU constantly will not be enough to keep it cool.

What CPU temperature do you see? You really should get a better CPU cooler, or improve the fresh air flow into the PC case.