[SOLVED] CPU throttling

[blackoutRN]

I've recently built a new system. When it is performing as expected, it works great. However, I am frequently getting system wide performance issues that don't seem to be tied to any particular task. The system takes such a performance hit that it makes it difficult to open a web browser. Sometimes, a system reboot will fix the issue and sometimes it won't. I finally noticed that whenever my system slows down, the cpu speed drops from ~4GHz to 0.4GHz. I spoke with an Intel tech who, after running some diagnostics, thought the cpu might be bad. I have since replaced the cpu with a new one and am experiencing the same issues. Does anybody have any ideas on how I can pinpoint the component causing the issue? At this point I feel it could be the power supply, motherboard, or even the cpu cooler if the system had difficulty identifying a cpu fan? While running throttlestop, I can see that the PKG Power voltages drop to about 3W when the system is slow and tend to be 25-30W when the system is running correctly. I've run benchmarks during both fast and slow periods and the results are about as expected- horrible when the system is slow, pretty normal when the system is fast. Where do I go from here? I have not done any over clocking or changing of settings (except for using XMP to set the ram to stated speeds).

Lian Li PC-O11 Dynamic
Intel Core i7-12700K (replaced with new)
MSI MAG Z690 Tomahawk DDR4
G.Skill TridentZ DDR4 3600
MSI MPG CORELIQUID K360
EVGA SuperNOVA 850 G5 850W
MSI GeForce RTX 2080 Sea Hawk X
Corsair Force MP510 m.2 2280 1TB (boot drive)
Samsung 970 EVO m.2 2280 2TB
Lian Li UNI Fan x9, connected to a single Lian Li fan controller
Asiahorse power supply extensions to the CPU power, motherboard power, and graphics card
Windows 11 Pro

 

[Lutfij]

What BIOS version are you on for your motherboard? Speaking of versions, what OS are you working with? If you're on Windows 10, please mention the version not the edition.

 

[blackoutRN]

What BIOS version are you on for your motherboard? Speaking of versions, what OS are you working with? If you're on Windows 10, please mention the version not the edition.

Bios is the most updated non-beta version, 7D32v11 obtained from the MSI website
Windows 11, all updates installed

 

[Phaaze88]

"... the cpu speed drops from ~4GHz to 0.4GHz."
That points to power throttling. The frequency doesn't drop quite as much if thermal throttling.
Loose/broken cpu EPS connections? Thermal throttling motherboard VRM?
is there anything else that would do it? The above are what I know of.

 

[uWebb429]

@blackoutRN
Run ThrottleStop 9.4.3 to test for BD PROCHOT throttling. Make sure to download this version. It supports 12th Gen CPUs.

ThrottleStop 9.6 Download

ThrottleStop is a small application designed to monitor for and correct the three main types of CPU throttling that are being used on many lapto

www.techpowerup.com

MSI motherboards used to have a LN2 switch on their motherboards. When this switch fails, it sends a throttling signal to the CPU using the BD PROCHOT signal path. When your computer is stuck at 400 MHz, open the ThrottleStop Limit Reasons window and you will likely see BD PROCHOT glowing red.

This has been a common MSI issue for many years. At least since the 4th Gen as my screenshot shows.

If you have this problem, try clearing the BD PROCHOT box on the main screen of ThrottleStop.

Some manufacturers are now locking BD PROCHOT so you can no longer disable this type of throttling. If the BD PROCHOT option is greyed out on the main ThrottleStop screen, you need to replace the motherboard. Post some ThrottleStop screenshots.

Edit - This is what you will see if BD PROCHOT is enabled and has been locked out by the BIOS.

Edit - I read the MSI manual for your motherboard but I could not find a LN2 switch. The online pictures were not detailed enough so this switch might still exist somewhere on the motherboard. It is still a good idea to look at the Limit Reasons data for any boxes lighting up red.

If both turbo power limits accidentally get set to 0, the same sort of throttling can happen. If you are using any MSI control center software, I would delete it while testing. The power limits can only be set to a maximum value of 4095.875. If software tries to set this power limit to 4096, what actually happens is the register that contains this information overflows and the power limit gets set to 0 instead. Another bug.

 

[blackoutRN]

Thanks for your response. I was finally able to get some ThrottleStop shots of both the slow and normal performance periods.
Normal:

Slow:

Clearly I can't change the BD PROCHOT option. So this means there is something wrong with my motherboard and I should contact MSI for a replacement? I really appreciate all the help

 

[uWebb429]

@blackoutRN
BD PROCHOT throttling is exactly what I thought.

BD is bi-directional and PROCHOT is processor hot. This is a signal path to the CPU. When a sensor shorts out or goes bad, it can send a constant signal to the CPU using this method. The CPU then reacts by using the same throttling method as if the processor was overheating and too hot. This locks the CPU to its minimum speed, 400 MHz. Obviously at 24°C, your processor is not hot at all.

There is no publicly available documentation from MSI that shows what sensors can send throttling signals using this method. The Intel tech is obviously not familiar with this MSI issue. Intel needs to update their diagnostic software so it can detect this common problem.

Your screenshot also shows that some 12th Gen motherboards are locking out BD PROCHOT so you cannot use ThrottleStop to disable this. You can have a look but there is likely no option in the BIOS to access the BD PROCHOT setting.

MSI motherboards have had this issue for 10 years. Do you really want another one? Even if MSI sends you a board that does not have this problem today, a year from now after the warranty is up, the problem might return. Consider asking for a full refund.

 

[blackoutRN]

@blackoutRN
BD PROCHOT throttling is exactly what I thought.

BD is bi-directional and PROCHOT is processor hot. This is a signal path to the CPU. When a sensor shorts out or goes bad, it can send a constant signal to the CPU using this method. The CPU then reacts by using the same throttling method as if the processor was overheating and too hot. This locks the CPU to its minimum speed, 400 MHz. Obviously at 24°C, your processor is not hot at all.

There is no publicly available documentation from MSI that shows what sensors can send throttling signals using this method. The Intel tech is obviously not familiar with this MSI issue. Intel needs to update their diagnostic software so it can detect this common problem.

Your screenshot also shows that some 12th Gen motherboards are locking out BD PROCHOT so you cannot use ThrottleStop to disable this. You can have a look but there is likely no option in the BIOS to access the BD PROCHOT setting.

MSI motherboards have had this issue for 10 years. Do you really want another one? Even if MSI sends you a board that does not have this problem today, a year from now after the warranty is up, the problem might return. Consider asking for a full refund.

That's a good point. I had a MSI motherboard for the previous 6 years with no issues, so I didn't realize this was a common problem with them. I didn't think much about a full refund being an option so I might actually go that route and get something else. You have been a major help and I think I finally have an answer! Wish it didn't take 6 weeks though but hopefully MSI will come through with a warranty. Thanks again!