What does 0x129 do that an IA VR limit doesn't?

[gcgc]

The description for the 0x129 microcode update is that it limits VID requests to 1550 mV. How is this different from setting the IA VR limit to 1550 mV, other than the former is disabled if you disable Intel Defaults, which at least on my board prevents underclocking?

[b0tlig]

Hello, I was wondering the same thing. I installed the new BIOS with the 0x129 microcode update for my 13700k, but just to be sure I set an IA VR limit of 1450 mV. Setting it lower than that brought my CPU clocks down, I didn't want that.

[RandyT_Intel]

Hello gcgc,

The 0x129 microcode update and setting the IA VR limit to 1550 mV both aim to control the voltage supplied to the CPU, but they operate differently. For microcode it is a preventative measure to avoid instability by capping the voltage requests. This update is applied via BIOS and is part of Intel’s default settings on the other hand it acts as a strict cap, ensuring that the voltage does not exceed the set limit regardless of the CPU’s VID requests. Microcode update controls VID requests (firmware level), while the IA VR limit controls the actual voltage supplied (hardware level).

Randy T. 

Intel Customer Support Technician 

[SmartOne_2000]

1.  Is the 0x129 microcode activated under the Intel Performance/Extreme default profiles only or other non-Intel profiles?

2. Doesn't the IA VR limit to 1550mV achieve the same thing as the 0x129 microcode? Never giving the CPU more than 1.55v?

3. If the microcode only works under Intel profiles, will setting the IA VR limit to 1550mv for non-Intel profiles achieve the same thing?

[RandyT_Intel]

Hello gcgc,

I hope you had the opportunity to review the information I posted. At your earliest convenience, please let me know so we can determine the best course of action to resolve this matter efficiently. 

0x129 microcode is activated only under Intel Performance/Extreme default profiles. Both aim to limit the voltage to 1.55V, but they work differently. The 0x129 microcode controls voltage requests at the firmware level, while the IA VR limit controls the actual voltage supplied at the hardware level. Yes, setting the IA VR limit to 1550mV for non-Intel profiles can achieve a similar effect as the 0x129 microcode however users can choose whether to use the Intel profile or a different one. Intel recommends using the Intel preferred BIOS settings.

Randy T

Intel Customer Support Technician

[RandyT_Intel]

Hello gcgc,

Since I haven't received a response from you, I will be closing this inquiry. If you need further assistance, please submit a new question, as this thread will no longer be monitored.  

Randy T

Intel Customer Support Technician