MSI has released new firmware for Intel 600- and 700-series motherboards, which allows you to turn off the CEP (Current Excursion Protection) function. According to the vendor's findings, disabling CEP can make your Intel 14th Generation Raptor Lake Refresh non-K processor run cooler without compromising performance.
Some users run their processors at stock, while others overclock them. Others like to undervolt their processors to make them run cooler while also saving some energy. However, MSI discovered that undervolting Raptor Lake Refresh non-K chips harms performance. The main culprit is the CEP. CEP is a protection function that impedes instability when insufficient voltage goes to the processor. When you undervolt Raptor Lake Refresh non-K SKUs, this triggers CEP, imposing a performance penalty on the chip through throttling.
MSI's tests revealed that the Core i9-14900 and the Core i7-14700 lost up to 40% performance when attempting to reduce the CPU AC Load Line to lower the CPU voltage with CEP enabled. When disabled, the Raptor Lake Refresh non-K chips didn't lose any performance and ran up to 16 degrees Celsius cooler.
Intel's premium Z-series chipsets and K-series chips have supported CEP disabling, so undervolting a K-series processor doesn't lead to any performance loss. However, disabling CEP on a non-K SKU wasn't possible until the latest Intel microcode update.
The microcode has enabled CEP disablement on a non-K processor and a non-Z chipset motherboard. However, there are still limitations. The microcode only brings the ability to disable CEP on the latest Raptor Lake Refresh non-K, Raptor Lake K-series, and Alder Lake K-series processors. Raptor Lake non-K and older chips are out of luck on this one.
Swipe to scroll horizontally
CPU / Chipset
Z790/Z690 MB
B760/B660 MB
14th Gen K-series
Yes (already supported with previous microcode)
Yes
14th Gen non-K series (BO stepping)
Yes
Yes
14th Gen non-K series (other stepping)
No
No
13th Gen K-series
Yes
No
13th Gen non-K series
No
No
12th Gen K-series
Yes
No
12th Gen non-K series
No
No
The CEP option is located inside the motherboard's BIOS. The exact location may vary depending on the motherboard model. However, the option typically resides in the Advanced CPU Configuration section under the Overclocking tab.
You might find two different CEP options: IA CEP and GT CEP. The former corresponds to the processor's cores, whereas the latter is for the chip's iGPU.
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(Image credit: MSI)
MSI is deploying the new firmware with the updated Intel microcode in two waves. The first wave consists of Z790 and B760 motherboards, while the second includes the B760 and 600-series motherboards. The first batch of firmware is already available for download at MSI's website, while the second batch is scheduled for a late March release.
One thing to note is that MSI's firmware is in the beta phase, so there are bound to be some bugs. If you don't own a non-K processor or don't plan on undervolting it, you can probably pass on this update.
Zhiye Liu is a news editor, memory reviewer, and SSD tester at Tom’s Hardware. Although he loves everything that’s hardware, he has a soft spot for CPUs, GPUs, and RAM.
Title not easy with this very specific hack. As far as I can tell, it is a fix for undervolted CPUs. It wont make CPUs in normal settings run cooler or faster.
That's pretty good for owners of those chips. Why not the 'k' SKU's too though?
Apparently the "k" SKUs already benefit from disabling CEP. I couldnt find it in my ASRock bios, but I noticed they posted a beta update as well with the fix.
That's covered, if only briefly:
"Intel's premium Z-series chipsets and K-series chips have supported CEP disabling, so undervolting a K-series processor doesn't lead to any performance loss. However, disabling CEP on a non-K SKU wasn't possible until the latest Intel microcode update."
So, perhaps the title should actually read: MSI details how to make your 14th Gen Intel CPU run cooler without losing performance — recommends undervolting and disabling CEP: )
If I understand correctly, the CEP-disabling only benefits people who are undervolting.
"One thing to note is that MSI's firmware is in the beta phase, so there are bound to be some bugs. If you don't own a non-K processor or don't plan on undervolting it, you can probably pass on this update."
