New Latitude 5491 High Fan on AC Power. Seems clock related

Our machine keeps overheating and being loud.  Once overheated, when trying to re-boot it says the power cord is the wrong one (it's the right one).  This is absurd.  Fix it, Dell!

Churchlady1

In other news. After the BIOS update. My mouse is constantly freezing up (which I assume means the USB hub in the thunderbolt dock is crashing or similar)

Updated all drivers to the latest. 

@ZeroAviation thanks for the update on the issue you are having with the 5491. Can you advise if you have tried a clean install of Windows with the latest BIOS and drivers to address your numerous performance issues alongside the docking station issue you are now experiencing?

I believe this may be the best way of understanding exactly what is causing the issues so I can feed it back to our engineering team.

I'll drop you a private message to get some service tag details of you.

Alan

BIOS 1.5.1 does not resolve the throttling issues.

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@Jeff.Dominiack wrote:

BIOS 1.5.1 does not resolve the throttling issues.

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@Jeff.Dominiack thanks for the update. The BIOS update contained an update to improve the thermal performance. Can you help me out with some additional details please so I can feed it back to engineering - 

a) Is there an improvement with the throttling compared to the previous BIOS revision
b) Have you seen a decrease in thermal temperatures during use?
c) When the throttling occurs if the system plugged in, running on maximum performance power plan and is well ventilated?
d) Is it specific to one application?
e) After how long does the thermal throttling normally occur?

Alan

I can elaborate on my experiences.

When I was using a TB16 on my 5591 Latitude, I would see thermal throttling alot.  Now that I have switched to an external GPU and use a Dell power supply to the laptop, I have no issues.  I would see the throttling happen where the clock frequency would get dropped way down to basically 800mHz.  This would happen whenever I would use program that was gpu or processor intensive.  Watching a 1080p video on twitch does it almost every time.  So would running a stressful benchmark test like Cinebench.

After using several programs trying to figure out what was going on, I saw in HWInfo that the throttling was loosely tied to the Dell Motherboard Temp0 sensor.  When it hit 70ish* C, the laptop throttles when using the TB16.  This happens regardless of fan speed adjusted in Dell Power Manager.

When I watch videos or game on the laptop with no TB16, the temperature exceeds 70*C on sensor 0 and does not throttle.  Same for using an external GPU 1080 plugged in via thunderbolt.  No throttling.  For me, it is very tied to using a TB16 with dual or even single 4k monitors and that Temp Sensor 0.

I have a chain I posted on my problems what I found.

https://www.dell.com/community/Latitude/Latitude-5591-with-TB16-Dual-Monitor-Temperature-Throttling/m-p/6236728#M9397

To share my experience with BIOS 1.5.1 and Dell Power Manager 3.1.0

Running one 32" QHD monitor on HDMI and one 24" monitor on DisplayPort through a TB16 dock.  Thermal Management set to Optimized in Power Manager and the Windows power plan is default Dell.

With both or either SpeedStep and SpeedShift enabled I immediately get core temps (all cores) of 95-100C. This is at startup with no load, and nothing changes until the system shuts down (regardless of what I run). The area just to the right of where the Thunderbolt cable plugs in (below the Esc key) is almost too hot to touch.

With both SpeedStep and SpeedShift disabled, core temps run at 45-50C.

This is a change from my previous post in this thread about the BIOS 1.4 where I was able to enable SpeedStep, but not SpeedShift.

The fan noise is noticeably louder than using BIOS 1.4.

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@RXUYDC wrote:

To share my experience with BIOS 1.5.1 and Dell Power Manager 3.1.0

Running one 32" QHD monitor on HDMI and one 24" monitor on DisplayPort through a TB16 dock.  Thermal Management set to Optimized in Power Manager and the Windows power plan is default Dell.

With both or either SpeedStep and SpeedShift enabled I immediately get core temps (all cores) of 95-100C. This is at startup with no load, and nothing changes until the system shuts down (regardless of what I run). The area just to the right of where the Thunderbolt cable plugs in (below the Esc key) is almost too hot to touch.

With both SpeedStep and SpeedShift disabled, core temps run at 45-50C.

This is a change from my previous post in this thread about the BIOS 1.4 where I was able to enable SpeedStep, but not SpeedShift.

The fan noise is noticeably louder than using BIOS 1.4.

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@RXUYDC Thanks for getting in touch. I have spoken with engineering and they are not aware of the throttling issue when thunderbolt is used. They would like some more information so they can investigate further. I'll drop you a private message to get your service tag details off you.

Can you confirm the following information for me please - 

a) If nothing is connected to the thunderbolt port, the system does not throttle performance during use?
b) As soon as the thunderbolt is used, the core temps increase and performance throttles back?
c) The system throttles irrespective of what device you have connected via the TB16?
d) Does the system shut down every time thunderbolt functionality is used?
e) Was the system exhibiting the same symptoms on previous BIOS revisions?

Would you be willing to system monitoring tool and send on the log for further analysis?

Thanks, Alan

Can you confirm the following information for me please - 

a) If nothing is connected to the thunderbolt port, the system does not throttle performance during use? The system does not throttle with out a TB16 connected. 
b) As soon as the thunderbolt is used, the core temps increase and performance throttles back? No the cpu and gpu core temp never goes up to throttle levels. It is the mother board sensor that causes the throttle temp sensor 0. 
c) The system throttles irrespective of what device you have connected via the TB16? No I am ussing a razor external gpu cage with a 1080 card hooked up via thunderbolt and have no throttle issues in that configuration. I am however not providing laptop power via thenthunderbolt link. With the TB16 yes throttling but the TB16 also is providing laptop power. 
d) Does the system shut down every time thunderbolt functionality is used? Never shuts down. It just drops the clock rate to 800mHz for a time then goes back up to normal then throttles again. 
e) Was the system exhibiting the same symptoms on previous BIOS revisions? Yes but I have not tried the TB16 with the most current Bios since moving to the external gpu when at my desk. 

Hi Alan,

I sent you the logs you requested and a couple of messages.

I am editing this response pending your review of the logs.

Thanks

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@HllCntryHrrcane wrote:

Can you confirm the following information for me please - 

a) If nothing is connected to the thunderbolt port, the system does not throttle performance during use? The system does not throttle with out a TB16 connected. 
b) As soon as the thunderbolt is used, the core temps increase and performance throttles back? No the cpu and gpu core temp never goes up to throttle levels. It is the mother board sensor that causes the throttle temp sensor 0. 
c) The system throttles irrespective of what device you have connected via the TB16? No I am ussing a razor external gpu cage with a 1080 card hooked up via thunderbolt and have no throttle issues in that configuration. I am however not providing laptop power via thenthunderbolt link. With the TB16 yes throttling but the TB16 also is providing laptop power. 
d) Does the system shut down every time thunderbolt functionality is used? Never shuts down. It just drops the clock rate to 800mHz for a time then goes back up to normal then throttles again. 
e) Was the system exhibiting the same symptoms on previous BIOS revisions? Yes but I have not tried the TB16 with the most current Bios since moving to the external gpu when at my desk. 

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@HllCntryHrrcane thanks for the contribution. @RXUYDC is suggesting that the issues are not down to TB16 and are concurrent with speedstep and speedshift being enabled in the BIOS. I would appreciate if you could confirm if the exact same is happening with your system and validate his findings.

If possible, could you not use your external GPU and replicate their setup i.e laptop, TB16 and whatever monitor you are connecting to it.

a) Does the system throttle during use with that configuration?
b) Now disable Speedstep and Speedshift in the BIOS, does the system still throttle?
c) Now disconnect the TB16 from the system and use it with speedshift and speedstep still disabled, does the system still throttle?
d) Now enable speedshift and speedstep in the BIOS. does the system still throttle?

Thanks, 
Alan

I have spent about 3 hours testing.  My tests and results are shown below.

I have disconnected my external GPU and reconnected my TB16.  I have also upgraded to the latest BIOS version and have a fresh Windows 10 install running 1809.  Running Speed Shift and Speed Step with Turbo on this first test.  The CPU Clock rate is running around 4GHz at idle.  CPU temps are about 60*C at idle.  Temp0 Sensor is about 56*C at idle. 

Running Cinebench CPU test results in a benchmark of 775 with temp throttling.  Temp0 Sensor reached about 80*C and CPU hit 98*C.  This temp throttling is probably CPU package based.  FPS was around 65fps with no temp throttling during that test but the Temp0 Sensor did climb to 63*C during the short FPS test with CPU Temps being about the same 63*C.  Running this same config, but just showing a twitch stream on 2 4k monitors at 60Hz refresh, Temp0 Sensor reaches 72*C while the CPU is around 75*C and the cpu throttles down to 800MHZ for about 40 seconds till it comes back up to 4.0GHZ and remains at normal clocks until Temp0 Sensor again approaches 72*C.  Temp0 Sensor goes down to 49*C during that throttle.  This is obviously Not CPU throttling but some other sensor calling the thermal throttle.  Watching video with this basically stock configuration is impossible as the CPU constantly throttles in this cycle.

Disabling the older Speed Step but keeping Speed Shift enabled resulted in almost the same results.  Slightly higher benchmark at 825 but still with CPU temp throttling.  FPS was again around 65fps.  Again, with a Twitch stream running everything is normal until Temp0 Sensor reached 67*C then I see the CPU crash throttling down to 800MHZ.  Odd that it is throttling at lower temps on Temp0 Sensor in this configuration, but it is consistent.

Disabling both Speed Step and Speed Shift yields the idle clock speed getting knocked down to 2.6GHZ and it never going up any higher.  Performance was noticeable degraded with a Cinbench CPU benchmark of 670 and no thermal throttling with a max CPU temp of around 66*C obviously because of the less clock rate and thus less power required.  The FPS test yields lower results as well at 51fps.  Likewise on the Twitch stream test, there is no thermal throttling happening with the Temp0 Sensor maxing around 57*C again probably because of the much less clock rate and power requirement.  Running with Speed Shift disable along with Speed Step disabled makes the laptop noticeable slower and basically unusable for high use workload.

With the old Speed Step enabled but Speed Shift disabled I saw similar results to the others.  On the CPU test, the system thermal throttled on the CPU temp.  Benchmark was a 795.  FPS was 66.  On a Twitch stream, I saw throttling when the Temp0 Sensor reached 67*C.  The interesting thing is the Temp0 Sensor reaches much higher in the Cinebench test and does not throttle so maybe it is a different sensor I have discovered causing the crash throttling down to 800MHZ when running a video stream.  It is not MX130 GPU temp either, so maybe the engineering team can tell us what to look at. 

Disconnecting the 5591 from the TB16, enabling Speed Shift and Speed Step, and running the same tests.  With Cinebench CPU test, I see a thermal throttle with a benchmark of 865.  Temp0 Sensor reaches about 80*C.  CPU temps get to max before the throttle and the clock rate drops to the same 2.7GHZ.  FPS test results about 60fps.  Running a Twitch stream on just the laptop monitor yields Temp0 Sensor staying around 65*C with no throttling.  Is this because of the TB16 or because it is just 1 monitor running 1080 instead of 2 monitors running 4K?

Same setup as the previous test but this time with 1 external 4k monitor connected via HDMI.  With a Twitch stream, this yields Temp0 Sensor temps around 82*C with no thermal throttling.

My conclusion is the same as I posted in my other chain.  Running no TB16 results in no throttling when watching video stream.  Running a TB16 results in crash throttling of the CPU down to 800MHZ in every combination except the one which Speed Step and Speed Shift are removed; however, then the CPU performance and clock rate stuck so low that laptop is at about half speed and unusable.

BIOS version is 1.5.1 in the above tests. 

@HllCntryHrrcane thanks for your very details response. I shall feed this back to engineering. Should they require more info I'll be back in touch.

Alan