Latitude 5591 with TB16 Dual Monitor Temperature Throttling

Did you try using ThrottleStop to disable BD PROCHOT?

I think PROCHOT only come into play with the proc temp when it hits around 98*C or 100*. It is no where close to that.

BD PROCHOT and PROCHOT are two different things.  Try disabling BD PROCHOT.  If it changes anything for the better, I will explain to you what this setting does.

I did some more testing.  BD PROCHOT and PROCHOT 98*C are both off but the system is still temp throttling when watching a video.  I have a USB dock on order to see if that acts any different than the Thunderbolt 3 Dock.  

The USB 3100 dock came in today. Plugged it in and the clock does not throttle even when temps get up around 85*C on that temp0 sensor.  Looks like something related to Thunderbolt is doing the throttling.  I uninstalled the Thunderbolt software and plugged it back in with monitors hooked up and still throttling.  It is something to do with the power draw/temp on the thunderbolt.  The crummy thing is I cannot use the USB dock with my dual 4k monitors and when the monitors are hooked up that way, Windows does not recognize any displays being connected to the MX130.  I guess it is thunderbolt with or direct connect only with the MX130.  No USB monitor connections.

Dell if you are watching, why is my system temp throttling when running on Thunderbolt but not temp throttling when running displays on USB?  The processor and temperatures do get up there when running on the USB but no throttling.    

More testing.  I tried running just 1 4k Display port on the TB16 and 1 monitor on HDMI direct to the laptop. Still get throttling.  Tried 1 monitor in TB16 on Displayport and 1 monitor in TB16 on HDMI and see if it still throttles...yep it still throttled after a few minutes.  Looks like any combination of 4k Monitor plug in via the TB16 results in throttling.  If I plug in monitors via USB dock, I don't have the throttling, but I have other issues with the graphics card and resolutions.  I have not tried just 1 monitor via the TB16.  I will do that next, but honestly that is worthless for my setup. 

FYI, then you uninstall the Thunderbolt software, it just comes right back like the Intel Thermal Management Driver.  

Looks like it throttles on just 1x4k monitor plugged in to the TB16 as well.  

Dell, my Latitude 5591 is temp throttling whenever I use my TB16 with a monitor plugged in to it.

Update.  I installed an external GPU (Razer Core X with EVGA1080).  I removed the TB16 and installed a Dell USB dock.  I installed the Razer Core X via thunderbolt but it does not supply enough power to power laptop so I have plugged in a power supply to the laptop.  I see no temp throttling now.  There is definitely something not right with the Thunderbolt and/or MX130 so that the system is temp throttling when video processing gets higher like when watching a video.  Normal office use does not cause it to throttle.

Sure wish I did not need a $1000 external GPU setup to hook up dual 4k monitors to this laptop.

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.

Update:  @Dell-Alan D  put me on contact with a local Texas/Oklahoma Dell Engineering team.  They have been great, although we have not solved the problem or really isolated it yet.

Update on our 5591 issues.  We have 2 identical laptops behaving the same way.  I have been working with the Dell Engineering team on trying to see what is causing this crash throttling when using the TB16.  We sent 1 laptop to Dell for evaluation.  They saw the problem but cannot replicate it in their lab on their equipment.  They sent the laptop back and dispatched a new TB16 to test with at our office.  It behaves the same way.  When watching a video stream, the laptops go from full CPU clock rate to 800Mhz every 2 minutes.  Dell is not going to do a capture and replace on both laptops and see if the backend engineering team can find the problem.  We have done all sorts of testing trying to isolate the problem, but so far nothing has been eliminated other than it is not specific to one laptop or one TB16 as we now 2 laptops and 2TB16s that behave the same.

It will be interesting to see if the replacement laptops throttle too.  That is my fear that this is a systemic issue and the replacement laptops will also behave as such, but hopefully it is just a batch problem.  Again, the work around for me has been to use an external GPU at a cost of an additional $1000 and my coworker just uses his laptop without external monitors.

Hi,

We have the same problems here although we only use WD15.

I have a machine with Windows 10 where the fan is running like **bleep**.

I have a machine with Ubuntu which is crashing under heavy load.

Any news from Dell on these problems?

We bought these machines to do heavy compilation jobs but as now they are not usable at all.

Johan @OTN Systems in Belgium

Any updates?

Yes.  Dell has taken both of my 5591 units into engineering testing. The replacement units they sent me also crash throttle with the same behavior. We have narrowed it down to not the TB16 as some units do this with directly connected monitors and somewhat with external gpu also. Looks to be an architectural issue or possibly a driver.  Given that 4 units now tested behave the same way, the issue is definitely not a hardware issue specific to one laptop and looks to be more systemic.  Dell is now able to replicate the issue with the 2 units I sent them and is investigating what may be causing it. Hopefully we will have more info soon.