Dell Latitude 5420 i7-1185G7 throttles to 400MHz on battery power

[disarray]

Hello TS community

My work laptop has been unusably slow when unplugged - even the mouse is lagging - meaning no way to work away from a power source regardless of charge. I've read and tried forum posts here, including one about another Latitude machine, and other resources online - but reset back to default settings now, hope to find help here to diagnose the issue and at least regain the ability to browse webpages and use outlook word excel etc. on battery power.

Please let me know what other logs or information I could provide, and thanks very much in advance.

Dell Latitude 5420 i7-1185G7 32GB RAM
Windows 11 Build 22621
65W Power adapter
1 to 2 external monitors (HDMI + USB-C)
No undervolting (though before I updated to Win 11 I had used Intel XTU to undervolt, seems it has been reset by now)

Things I tried, and have since reset, with no improvement. Though sometimes the max speed can be maintained or down to around 1GHz for a few minutes after unplugging but eventually goes down to 400MHz
- intelppm start value set from 3 to 4 in Registry Editor
- unchecked BD PROCHOT
- Power Limit 4 Max set 0 in TPL
- checked MMIO Lock in TPL
- checked Speed Shift EPP at 128, 96, 225
- Speed Shift in TPL: Min 4/24 Max 42/48
- PL1 PL2 set 60/100 in TPL

Once I plug in the power adapter, speed returns to normal.

Screenshots on 65W Adapter (220V): All 3 EDP Other flashes red every few seconds, PROCHOT 98C sometimes red

On battery power: PL2 solid red for Core and GPU, flashes red for Ring

 

[PHVM_BR]

Check the battery life with HWiNFO64.
It may be that the battery is at the end of its life and the CPU is severely limited when unplugged.

Try unchecking BD PROCHOT in the Throttlestop main window.

No undervolting (though before I updated to Win 11 I had used Intel XTU to undervolt, seems it has been reset by now)

i7-1185G7 cannot be undervoltaged.

 

[disarray]

Thanks for the suggestion - assuming i found the correct section, wear level is 49.6%, is this an expected outcome of a well-used battery?

Unchecking BD PROCHOT and unplugging gives me around 2 minutes of performance then it goes back to 400MHz with PKG Power under 5.0 W on the main screen. Even getting this screenshot was quite a struggle and I have to plug in again to scroll this page and type smoothly.

 

[PHVM_BR]

Thanks for the suggestion - assuming i found the correct section, wear level is 49.6%, is this an expected outcome of a well-used battery?

Unchecking BD PROCHOT and unplugging gives me around 2 minutes of performance then it goes back to 400MHz with PKG Power under 5.0 W on the main screen. Even getting this screenshot was quite a struggle and I have to plug in again to scroll this page and type smoothly.

View attachment 359808

The battery shouldn't be the problem.

Have you tried blocking the power limits by checking lock MMIO?

Another suggestion is a clean install of Windows and update all Dell drivers. Your changes in the registry editor may have messed something up...

 

[Lew Zealand]

Thanks for the suggestion - assuming i found the correct section, wear level is 49.6%, is this an expected outcome of a well-used battery?

Unchecking BD PROCHOT and unplugging gives me around 2 minutes of performance then it goes back to 400MHz with PKG Power under 5.0 W on the main screen. Even getting this screenshot was quite a struggle and I have to plug in again to scroll this page and type smoothly.

View attachment 359808

That battery is end-of-life. 50% is bordering on useless and it's not necessarily the charge, it may be so weak that it can't deliver the voltage or amperage the processor needs so it defaults to limp mode at 400 MHz. First thing I would do if I was using that laptop (BTW I have that same one with the i7) would be to replace the battery.

However as reinstalling Windows is pretty quick and it can't hurt, try that as well as PHVM_BR suggested.

 

[unclewebb]

@disarray
Did you buy this laptop when it was new or when did you first start having this problem? Lots of Dell laptops use absurd power or current limits when running on battery power which causes throttling to 400 MHz. I am not sure how Dell got away with building laptops like this but they did. Not enough people complain.

replace the battery

I would not waste my money on a new battery if this Dell laptop had the 400 MHz throttling problem since it was new. A new battery will not solve the problem if the problem is poor design.

checking lock MMIO

I would definitely do that. Checking the MMIO Lock box can solve a lot of throttling problems in the 11th Gen laptops.

Many power limit throttling problems were programmed by Dell into an embedded controller (EC) that ThrottleStop does not have access to. There is no simple solution for EC throttling problems in many Dell laptops.

I would set the IntelPPM Start registry item back to its original value. I would also check the Speed Shift box in the TPL window.

 

[disarray]

Thank you all for the feedback!

The company buys laptops new, this unit is from 2021 and was fine when I inherited it around 2 years ago. This problem presented around when I upgraded to Windows 11 (1 year ago), but that might just be a result of age since outside of travel and meetings I generally run it plugged in and may have ruined the battery life

I'm trying out the settings you suggested which helped for around 10 minutes after unplugging, throttling again which I'm not sure if it's related to a temperature spike to 90+C.

Would it be advisable to select Speed Shift EPP on main screen as well?

Failing all else, I think I might just request for a battery replacement or laptop replacement... Unfortunately the company insists on using Dell only.

 

[unclewebb]

This problem presented around when I upgraded to Windows 11

Some computers automatically updated the BIOS during the upgrade to Windows 11. That might have changed how your laptop performs when running on battery power. BIOS updates for laptops rarely make things better.

I generally run it plugged in

I have been using my Lenovo laptop mostly plugged in for 10+ years. It still has the original battery. It has no problem running at full speed when it is running on battery power. Only Dell laptops seem to throttle like you are experiencing when unplugged.

which helped for around 10 minutes after unplugging

Check the Log File box on the main screen of ThrottleStop before switching to battery power. This will create a record of CPU performance and will record what the reasons for throttling are. Some Dell laptops will use severe power limit throttling as soon as they get up to approximately 90°C. Intel says this is not necessary but Dell decided to create their own in house throttling schemes. Even after the temperature is reduced, they can continue to power limit throttle.

Use your laptop for at least 15 minutes while logging data. Make sure while logging data that your laptop goes through one of these throttling episodes. The log file will be in the ThrottleStop / Logs folder. Attach a log to your next post so I can have a look.

Speed Shift EPP

As long as Speed Shift is checked in the TPL window, you do not need to check the Speed Shift EPP box on the main screen of ThrottleStop. Windows 11 is designed to use Speed Shift to control your CPU speed whenever this feature is available. Intel first introduced Speed Shift Technology to their 6th Gen CPUs. The BIOS of a computer with an 11th Gen processor should automatically enable this feature. If you find the Speed Shift setting in the BIOS, it should be enabled.

 

[disarray]

Please see the settings and log. I've also updated what Dell drivers I could, but left the BIOS (11/10/2023 v1.33.0).
This time it almost immediately throttled, and once plugged in immediately resumed normal. Definitely won't be buying from Dell for my personal devices.

From what I've read on the forum, seems I should try to change PL1/2 power limit controls? But I'll wait for expert advice.

Thanks very much for helping out

 

[unclewebb]

Your log file shows and documents what your Dell laptop is doing.

   DATE       TIME    MULTI   C0%   CKMOD  BAT_mW  TEMP    VID   POWER
2024-08-22  10:04:15  POWER STATUS CHANGE
2024-08-22  10:04:16  43.23   60.5  100.0       0   82   1.1000   30.2
2024-08-22  10:04:17  42.92   30.3  100.0       0   65   1.2775   25.3
2024-08-22  10:04:18  43.16    9.8  100.0       0   64   1.2649   10.1
2024-08-22  10:04:19  42.81   14.4  100.0       0   75   1.0950   15.4
2024-08-22  10:04:20  28.19   30.4  100.0       0   57   0.5974   14.6   PL2
2024-08-22  10:04:21   4.00   74.1  100.0       0   56   0.5974    5.2   PL2
2024-08-22  10:04:22   4.00   63.0  100.0       0   56   0.6000    4.5   PL2
2024-08-22  10:04:23   4.00   59.7  100.0       0   56   0.6000    5.0   PL2
2024-08-22  10:04:24   4.00   48.0  100.0       0   55   0.6000    4.4   PL2
2024-08-22  10:04:25   4.00   51.1  100.0       0   55   0.6000    4.9   PL2
2024-08-22  10:04:26   4.00   62.0  100.0       0   55   0.6000    5.2   PL2
2024-08-22  10:04:27   4.00   81.0  100.0       0   55   0.6000    5.6   PL2
2024-08-22  10:04:28   4.00   58.0  100.0       0   55   0.6000    5.1   PL2

Within 5 seconds after unplugging your laptop, the MULTI column indicates that your laptop has gone from approximately 4300 MHz down to 400 MHz. Hard to understand how anyone masquerading as an engineer could think this sort of extreme throttling would be OK to a paying customer. You are not alone with this issue.

PL2 in the far right column shows the reason is power limit throttling. The temperature is fine and power consumption is only 4 or 5 Watts. There is no legit reason why your laptop is running as slow as it is. This kind of severe throttling makes an otherwise decent laptop completely unusable when running on battery power.

The MSR and MMIO power limits that ThrottleStop has access to are being ignored. This confirms that Dell is likely using an embedded controller (EC) to force feed a low ball PL2 power limit to the CPU. The CPU constantly compares the three separate power limits and uses the lowest value it finds. Non stop throttling is the result. There is no known fix for this common Dell issue.

If you have money to burn you can try replacing the battery and the power adapter. If that does not work, then you can consider replacing the motherboard with a used one that might have the exact same problem. You can send it to Dell but you might end up being told that this type of extreme throttling is "by design" which is what other users have been told.

This bug has been around for years. I get almost as frustrated as users get when there is no simple solution that is guaranteed to solve this problem. Let me know if you ever come up with a solution for this.

 

[disarray]

Thank you so much for looking at my problem and sorry that you have to share in the frustration that is using a Dell product... Their support forums only return results for putting windows high performance mode which is disappointing to say the least.

I ran a few more logs but the result is similar, though randomly the multi value will stay high for a few minutes before going down to 4. At least I have some temporary closure knowing there's nothing else to be done - I'll keep the TS settings for now.

I've put in a request for a new battery and will be updating once I get it replaced. Might just shell out for a PD portable charger for use at airports, etc. if it still doesn't work out

 

[remixedcat]

i7-1185G7 cannot be undervoltaged.

not just on dell systems? even lenovo, acer, hp, etc??

 

[unclewebb]

The 11th Gen G7 series cannot be undervolted. Intel removed that feature. Intel also removed undervolting from 12th Gen and newer mobile H series CPUs.

 

[Darmok N Jalad]

If the problem is only in battery, then I really do think it’s the battery that’s the problem. Modern CPUs have much higher voltage spikes to reach those boost speeds, and I’m betting that the well-worn battery simply isn’t able to accommodate that, so the device is in gimp mode unless plugged in. These days I even question that a laptop can run at full speed with a bad battery, since they often ship with underpowered AC adapters that can only keep up under light use or idle charging. The voltage spikes in boost might even need the battery to offset what the AC adapter cannot provide.

Consider also that most laptops today default to settings where boost clocks get reduced when unplugged, likely to save battery power. You will only get its top performance when on AC power.

You could always crack it open, clean it out, and reapply thermal paste to see if that helps, but it sure looks like a battery issue to me.

 

[remixedcat]

The 11th Gen G7 series cannot be undervolted. Intel removed that feature. Intel also removed undervolting from 12th Gen and newer mobile H series CPUs.

well that's pants

 

[silentbogo]

With Dells it's complicated ever since Haswell. Any power-related issue may cause this behavior(CPU stuck at 400MHz), and that includes issues with motherboard and SoC itself.
Since you have no issues on charger, I'd suggest replacing the battery as a sanity check, assuming you buy it from somewhere with a 2-week return window. And if not - just keep it as a spare, cause these things tend to puff-up and die after a couple of years of moderate use.
In my lifetime I've seen many cases where these things would happen from faulty VRM elements(glitchy PWM controller or pre-failing SMPS etc). Latest one was my friend's Inspiron 3793, which initially had the same symptoms(low self-esteem while running on battery ), and few days later an PWM controller on CPU VRM blew up, leaving a sizeable crater in PCB and releasing enough magic smoke to make its way out of gigantic 17" chassis and scare the s$%t out of his cat

 

[remixedcat]

With Dells it's complicated ever since Haswell. Any power-related issue may cause this behavior(CPU stuck at 400MHz), and that includes issues with motherboard and SoC itself.
Since you have no issues on charger, I'd suggest replacing the battery as a sanity check, assuming you buy it from somewhere with a 2-week return window. And if not - just keep it as a spare, cause these things tend to puff-up and die after a couple of years of moderate use.
In my lifetime I've seen many cases where these things would happen from faulty VRM elements(glitchy PWM controller or pre-failing SMPS etc). Latest one was my friend's Inspiron 3793, which initially had the same symptoms(low self-esteem while running on battery ), and few days later an PWM controller on CPU VRM blew up, leaving a sizeable crater in PCB and releasing enough magic smoke to make its way out of gigantic 17" chassis and scare the s$%t out of his cat

this precision 3550 doesn't throttle at all even on battery. still the full speed even when producing music it goes to the full speed on battery and even still performs the same as on the charger when I have the cpu governor on performance mode. this is a i5 10310u tho. mabye they introduced some throttling on 11th gen and onward or more battery protections??? and I still get decent battery life even at full performance governor making music can get 3-4 hours on it at full speed. and 6-7 with medium usage with web+yt+etc...

btw partspeople is cheap for batteries and they are dell official too.

 

[Lew Zealand]

FWIW I have a secondhand Dell 7420 with the same CPU which looks close enough to the 5420 here. Knowing how Dell builds things they are very likely the same motherboard with some small component differences. I have extensively tested the power capabilities of mine as I wanted to do light gaming on it and it does contain the usual Dell suck. Here's how:

The processor is rated to 35W (Intel Power Gadget reads it as a 35W CPU) and will draw over 40W for short loads and boost to near top speed and amazingly does not thermal throttle. However after a few seconds of 100% CPU or GPU use, it'll throttle to 28W. Then 22W after 30 seconds or so. And then it slooowly slides down to 17W and 13W and finally to 11W. Sometimes it'll recover to 17W but it'll oscillate in the 11-17W range, most often in the lower part of this.

And the CPU is at 55C at this time. Dell actually put in a capable cooling solution and crippled it with this power limitation. Frankly 22W would have been a nice improvement over the previous 7480 and 7490 which were set at 15 and 17.3W max (also extensively tested) and the cooling solution easily manages this. This behavior is identical on battery or wall power and my battery is in great shape.

That weird Wattage variability almost looks like the power delivery is inadequate and either not up to spec or not cooled properly, heating up past its internal limitations.

That said, in CPU-only use it does stay above it's rated clock speed though of course Turbo speeds longer than a minute are only a dream. But it's not stuck at 400 MHz on battery or plugged in like OP's machine. That one may be defective or it may run properly with a better battery. I've seen machines that do not run at full speed with an undetectable battery, but OP's is detected even if severely degraded. And it could be that Dell puts it in Limp-Home mode if the battery health goes under 50% or whatever other arbitrary number they choose. It's Dell, good luck predicting the method of their cost cutting or power limiting or poor design or price point narrow-mindedness.

 

[disarray]

We order from dell directly I believe. It will take around 2 more weeks, and I'll come back with an update

 

[disarray]

Hey everyone, thanks once again for chiming in.
Got the battery replaced today with much better useability now, as you can see from the log.

I'm only seeing yellow warnings in TS Limit Reasons. Fingers crossed that everything's fine but if not I'll come back to warn future dell users not to put too much hope on replacing battery... lol

 

[ChemicalDruid]

I'm only seeing yellow warnings in TS Limit Reasons.

FYI this means there was throttling even for an instant - red for current throttling, yellow for past throttling.

 

[remixedcat]

Just curious... what's laptop brand don't do this throttling??

 

[Lew Zealand]

Just curious... what's laptop brand don't do this throttling??

Hard to give one manufacturer a complete pass as their top end gaming laptops may not throttle while their budget models may. I'll recommend what my brother in law did after too many throttling office laptops: He bought a mid-high end gaming laptop a couple years ago and it's a little heavier than his previous one but it continues to perform as he needs it to. It's an Asus with Ampere, I think 3070, in it.

 

[Frick]

Hard to give one manufacturer a complete pass as their top end gaming laptops may not throttle while their budget models may. I'll recommend what my brother in law did after too many throttling office laptops: He bought a mid-high end gaming laptop a couple years ago and it's a little heavier than his previous one but it continues to perform as he needs it to. It's an Asus with Ampere, I think 3070, in it.

AFAIK even those "mid high end" stuff can be iffy.

 

[remixedcat]

Gaming laptops are a bitch and a half to repair tho...
Watched Salemtechsperts fix gaming laptops and a lot of them aren't the easiest to repair or upgrade.

Also parts availability isn't as good either...