Does anyone have an issue with an Inspiron CPU being stuck at the lowest frequency on battery power?

I think the issue may be with a high IA CPU core power consumption. On both HW Monitor and HW Info, the IA core power consumption is around 8-18 watts on idle and around 18-23 watts when playing a video. On AC power, it does not power throttle and the video plays fine.

On battery when idle and not playing a video, the frequency drops down to 0.40 GHz and HW Info says there is power limit throttling with PL1. When playing a video, it stutters. When I run CPU Z stress test, it is capped at 20% in Task manager with the frequency is stuck at 0.40 GHz.

On my Lenovo with a 6th generation i5, the IA core power consumption is 1-2 watts when idle and around 5 watts when playing the same video.

I think my Inspiron is power limit throttling because of this high baseline IA core power consumption even when idle on battery. Does anyone know how to fix this? Does anyone else have this problem? Am I the only one with this issue?

What idle IA core power usage is other people getting in HW Monitor and HW Info with their Inspiron 5379?

This is starting to feel more like a blog post than a forum post asking others for help or suggestions. However, I guess someone may find this information useful if their laptop has a similar problem so I am posting this update.

I talked to another Dell customer and explained to her the issue with my laptop and told her that I wanted to send in my laptop to be inspected. I told her that the prior service rep had not been able to fix the issue, but she said that normally she tries to troubleshoot issues over the phone first. After over 20 minutes of her trying to look up a solution to the power limit throttling problem without success, she agreed to have me send it in. The laptop was received by Dell, and a service tech replaced the hard drive then shipped it back to me. I was disappointed because I knew it was not the hard drive. I had the power limit throttling issue using 3 separate SSDs and a Windows 8 OS booting from a USB flash drive so this issue was separate from the HDD it came with. When the laptop came back, I immediately booted it up and the power limit throttling issue was still there. However, when I ran the Dell hardware diagnostic program, it gave an error message with the HDD. I had ran the full diagnostic test a few weeks earlier without a problem. I was upset because now I had a new HDD error on top of the power limit throttling problem. I tried unplugging and replugging the HDD making sure the cable was secure and still got the same message.

I then talked to another customer service rep and after explaining the problem and discussing it for a good length of time, he said they would have a specialized service technician inspect it. I sent it back in and this time wrote a note to please make sure the power limit throttling problem was resolved after the HDD was replaced. I also told them to use the HW Info program, CPU Z, program, and my test video after replacing the HDD. I had included all this informatoin the first time I sent it in, but the first tech never did anything but replace the hard drive. This time however, all the time I had spent finally paid off. Here is the online note I got about the repair.

Certified Technicians performed diagnostics on the defective unit and actions can consist of repair to connections, reseating components, or replacement of defective parts which are listed below:

DNKMK - Motherboard

0285K - AC Adapter

Y3F7Y - Battery

KWHKR - Mechanical Hardware And Plastics (bottom case of laptop)

P6R56 - Hard Drive

Even though both the short and long Dell hardware diagnostic test and Intel diagnostic test did not show anything wrong before the first time I sent it in, and only the HDD had an error message the second time, the tech needed to replace a lot of parts to hopefully resolve the issue. This just shows that the diagnostic tests do not detect everything. I cannot wait to get the laptop back and test it out. Hopefully it will now run like it is supposed to. If I had not been persistent in proving that there was a power limit throttling issue, my issue would have been swept under the rug and I would have been stuck with a lemon. After all the days I spent trying to figure out the problem, it is hopefully finally coming to an end. I am grateful to the second service tech who listened to my issue better. Cross my fingers for when I test the laptop when it comes back.

I got the laptop back and it STILL HAS THE SAME PROBLEM. I am at m wits end. 

I figured if the motherboard was replaced and it still has the same problem, then it must be the smaller IO board that is causing the issue. I detached that cable, but it still has the same problem.

I installed Battery bar which monitors the power discharge rate and compared that with the HW Info values. There is an odd discrepancy. The HW Info CPU Package power is around 15-23 Watts. The battery bar discharge rate is about 5,000-7,000 mWatts or 5-7 Watts. The battery life seems to be a out 6-7 hours with a battery size of about 40WH so the 5-7 Watts is likely more accurate. It seems as if the sensors are giving a false reading of 15-23 Watts which causes Power limit throttling, but the actual power usage is lower which is why the battery life is still pretty good. This seems to be a bigger issue with Dell/Intel and the software. It may have to do with the DPTF but I would rather not disable it as that may cause overheating damage. 

If anyone has the 5379, could you please run HW Info or HW Monitor and post what your IA Cores Power and CPU Package Power are and whether you have the i5 8250u or the i7 8550u? This will let me know if this is a product wide issue or just an isolated issue with my laptop.

Intel has a nice tool to troubleshoot CPU's to make sure they are performing correctly. Sounds like maybe your CPU is throttling down because of overheating possibly which would prevent it from clocking up. One possibility and I assume you have checked your power settings and bios to make sure everything is set to default. 

Johnnythegeek,

Thanks for responding. You are the first person who has tried to help so far.

I already ran the Intel Processor Diagnostic Tool and everything passed. The Dell Diagnostic Tool also passed.

The BIOS has been changed many times in my attempts to troubleshoot this. This includes many resets to Factory default settings. Unfortunately, nothing helps.

CPU max has been set to 100% and CPU minimum has been changed to many values from 5% up to 100% without any improvement.

HW Info shows the CPU Package Power is often at 20 watts when idle without any active programs, except HW Info or HW Monitor which I use to check the Package Power. I only ever have one running at a time, because I  know that running both can cause problems.

I have read online about people with the XPS with an i7 m processor with similar issue, but they never found a solution and returned their laptops. Unfortunately, mine is outside the return window.

If anyone has the 5379, please post your CPU package power with either HW Info or HW Monitor. Thanks in advance.

I answered this here: https://www.dell.com/community/Inspiron/Power-limit-throttling-Inspiron-13-5379-Post-your-CPU-Power/m-p/6105655/highlight/true#M23816

Thank  you very much for the reply. This lets me know that I think there is something wrong with my laptop. Your core power is around 8watts when mine is often around 20watts when idle. I let it sit for around 30 minutes and it may drop down to 5 watts. Sometimes it does not drop. But even if it does and I open up Chrome browser or play a video, the core power jumps up to 20-30 watts and I get power limit throttling.

On Throttlestop, you do not have throttling issue which mine often has.

Your laptop seems to get very hot with the CPU temperature at 75 degrees Celsius. MIne is usually around 30-40s degrees Celsius but that is because it has power limit throttling with the CPU frequency stuck at 400MHz. You could try setting the CPU power max at 95% and see if it keeps it from getting too hot. It will make it slightly slower, but you may find a compromise between power and temperature/fan noise. Thank you for the post!

I think it is finally fixed!

I talked to customer support several times again and they tried to troubleshoot it remotely with no success.

They finally had me send it back in for the third time. I looked at the package insert from the last repair and noticed that the motherboard had not been replaced. Instead, it said that the motherboard was removed and fixed. So it seems that it was never actually truly fixed.

This time they actually said the replaced the motherboard and voila! The laptop finally seems to work correctly. There is no longer a power limit throttling issue. When playing the video, the core power is less than 1 watt and the package power is about 1.5 watt with HW Info. The core power used to show 20 watts before the replacement. I knew it had to be something wrong with the hardware/motherboard. With how much customer support time, shipping back and forth 3 times, tech hardware support, and replaced parts, it would have been cheaper if they had just fixed it correctly the first time and replaced the motherboard. However, I am sure they thought they could save money by trying lesser fixes first. But they never checked that the problem was resolved before they shipped it back to me the first two times. This seems to be wasteful in time and money on Dell's part. There is also the large amount of time I wasted.

Before this was fixed, I planned to never get a Dell again. Now, I may reconsider it in the future, but I was advised by a laptop repair store that if I buy another Dell, get a Latitude and not an Inspiron. I think I will follow that advice and hopefully save many days of my life in troubleshooting issues.

I still remember the first customer service rep I talked to on the phone who had me run the Dell hardware test program which showed no issues. He then told me that it was a software issue and not a hardware issue and told me I had to pay a few hundred dollars for Dell software support. For other people with issues with their laptops, realize that the Dell hardware test (both the short and long test) and the Intel hardware diagnostic program test only certain things and do not detect all problems. A clean test does not mean that there is not a hardware issue.

Another time, a supervisor tried to explain to me the architecture of a CPU and how it was normal for the CPU to drop in frequency and that my laptop was operating normally. It was only after I argued that the frequency should not be stuck at 399 MHz and the Task manager max performance stuck at 20% during a stress test that he finally agreed that my laptop was not operating normally.

I am grateful that my laptop was fixed, but dealing with Dell customer support has been very very very exasperating. I hope that no one else has to deal with this same problem. If so, good luck to you as you will need it.

Has the issue came back since you last posted this? Also, how's the laptop after owning it for a few months after drivers updates and whatnot? Battery life, SSD speeds, screen brightness, speaker quality. I heard all of those things to be kind of controversial with this laptop, so I was wondering what your thoughts are because I am planning on purchasing one soon :)

Battery life is good but I do not do much gaming. The hard drive is slow so I had replaced it with my own SSD. The speakers are not very good and sound tinny. Screen brightness is fine for me but I do not use it outdoors.

Power limit throttling has not recurred but I do not expect it to as the motherboard was replaced. As I said above, I would not get an Inspiron and would get a Lattitude if I buy another Dell in the future. However, I would probably get another brand unless there was a great deal on the Lattitude.

I have never had so much issues with a laptop and I have had 7 laptops so far of different brands. The technical service at Dell took 3 tries to finally fix the same issue which means they never checked to see if the problem was resolved the first 2 times after their attempted fixes. Very frustrating.

I'm not having power throttling on mine I don't think, it seems to run at 0.8-0.9 GHz when I do light stuff, but it never feels slow. Mine is the i7-8550U variant by the way. I think I know what the culprit was for the speed being "stuck", right click on the battery icon, then go to "Dell extended battery life options" and toggle "Enable Dell Extended Battery life" to OFF. When I had it on it got rid of my power slider, and locked my speed at 0.39 GHz or something.

This is the power slider: https://filestore.community.support.microsoft.com/api/images/a1a0ab7f-d8c2-45bd-928e-528764febfe8

But as soon as I toggled it OFF, the slider came back and my CPU speeds went back to normal. I think it's a software bug to be honest.

If you look at one of my earlier posts, Dell fixed the problem by replacing the motherboard. At first they tried to "fix" the motherboard but was unsuccessful. The motherboard replacement fixed the problem. Thanks for your response though. When I first posted this, not many people responded and I felt posting here for help was pointless, but after a while I got a few responses which was nice. It is always nice to see people trying to help others out. Unfortunately my laptop problem was an issue only a hardware replacement by Dell could fix.

This issue is really weird, ive never heard of anything like it.

Mine (on battery) remains around 0.90-2.10 ghz.. 

8gb ram

1tb hdd

128gb ssd (boot device - latest ver of win 10)

i5 processor

I might have a slightly different model, though.