Dell XPS 15 9550 Power Limit Throttling

Hello,

I seem to be having Power Limit Throttling issues when gaming. I've used XTU to monitor my laptop and I've noticed that while gaming when the Package Temperature reaches 79C in particular, my gaming performance drops drastically. In XTU, I can see the Power Limit Throttling up at 100% and my Core Frequency down to 0.80 GHz. I have tried to address this problem once before by following what someone wrote down on the dell forums which seem to help a little, but the problem is still there and I could not find any answers regarding this matter there. In the latop's power settings, I've set the Minimum Processor State to 5% and the Maximum to 80% (By default they were both 100%). I have also tried undervolting to -145 through XTU after reading through some of the threads here. After undervolting, I am getting lower temperatures, but still getting the throttles.

I am using a Dell XPS 15 9550 (Core i7-6700 2.60GHZ, 16GB RAM, GTX 960m 2GB RAM, 512GB SSD).



Thank you for your help.

EDIT: I have tested these changes for 1 month now and I am no longer having throttling issues while gaming. I've undervolted the CPU using Throttlestop by -140mv. The Min & Max Processor State in Advanced Power Settings are at 5% & 80% respectively. As of now while gaming (Starwars BF at 1080p - Medium Settings - 100% Resolution Scale), I can see Max CPU Temp: ~75c and Max GPU: Temp ~83c. But no throttling after 1 month UV with TS.

 

repasting the CPU/GPU will help and addressing the VRAM pad that only makes partial contact to keep temps down may help as it could also be thermal related.

As it is basically a higher wattage chip with a hardware cap on it to keep it under 45w that part is quite normal as it is the only way to keep it under 45w when stressed.

 

As GonZ0 notes, there is a lot of benefit to repasting the CPU/GPU and fixing the VRAM pads; those are easy and provide good results for low cost / low effort. At the limits, I think these fixes are required because they are defects out of the factory.

I had the same odd "Power Limit Throttling" problem at ~79*C. It appears to be buggy Intel XTU software. Try killing XTU and undervolting with Throttlestop. To be clear, the creator of ThrottleStop said one can not run XTU and ThrottleStop together. See quote below or search my posts for more details if you like.

(Edited misinformation)

OTHER IDEAS
- My buddy is a supercomputer engineer (specializing in thermals) who insists that the turbo usually is a "laptop marketing gimmick" and should be disabled in the 9550 because upside is short-term but the thermal impact is "devastating" in such a small box (with suboptimal thermals). [ThrottleStop seems to keep my CPU at 3.1Ghz and in control so my buddy's concern is not too relevant for my 9550 + ThrottleStop setup]

- The designer of ThrottleStop talks about the thermal benefit of sorting out processes here:
http://forum.notebookreview.com/thr...ftware-problems.784691/page-101#post-10278788

 

Or do what I do and make a throttlestop profile that turns turbo off at 80C.

 

I have checked the "Disable Turbo" option in TS, I've read the guide for using TS, but I'm not sure of what to do to undervolt with this program.
I'm guessing that doing so would help with the heat issues from what I've read so far.

Thank you.

 

This is a quick primer
http://www.ultrabookreview.com/10167-laptop-undervolting-overcloking/

And this thread has detail directly relevant to your 9550
http://forum.notebookreview.com/thr...rature-observations-undervolt-repaste.785963/

 

Should I undervolt the CPU Cache as stated in the undervolting guide as well?

Thank you.

 

I'd listen to the guide. He seems like he knows his stuff.

 

Alright, thank you so much for your help Eason and Pressing.

 

Anybody else getting an error that their CPU, i5-6300HQ is not supported by Throttlestop?

 

Have you tried using the Beta 810 Version?

 

thanks mate, didn't see that...haven't used it in a while

getting throttling when playing BF4 and Witcher 3 except it kicks in at around 60 - 70 degrees,

brings the cpu down to 800mhz and keeps it there for a good few minutes

surely this should not be happening..

 

It takes into account more than just the CPU temp, it is combined with other sensors so I doubt it is doing anything wrong if the VRM, PCH, Chipset and GPU are hot as well. while it may keep it from initially throttling it can't stop the inevitable heat build up in other parts of the laptop that will in the end force the CPU/GPU to low clocks for longer while the other parts come back to normal temps.

Personally I think it is a bad idea for the longevity of the laptop so I don't use it.

 

@madaimer - If your CPU is throttling down to 800 MHz at only 70°C, that is just bad design. I would definitely be using ThrottleStop in a situation like that. Make sure BD PROCHOT is not checked and see if it is still throttling. This simple change might make a big difference. Your CPU will still throttle if it ever gets too hot but it might prevent it from throttling at only 70°C.

ThrottleStop has been out for years now and I can only think of a single person who has damaged his laptop while using ThrottleStop. He was grossly overclocking his laptop at the time so it might have failed anyhow whether he was using ThrottleStop or not. Most users that take the time to contact me are usually 100% happy that they can finally use their laptop at the Intel rated and promised speed. So many of the throttling schemes that Dell and other manufacturers use are not well thought out.

 

The GPU is sitting at the low to mid 70°C under load, all other components seem to be within very normal ranges.

It's a bit odd that it's throttling down at such a low threshold.

My previous laptop (Sony Vaio 13p) would throttle the GPU at 85°C and the CPU at around 89°C?

Lastly, the benchmarks and reviews of the laptop seemed to indicate that the laptop had very good internals...

Most people don't seem to be encountering any throttling, if they do it seems to drop dynamically rather than immediately to 0.8ghz?

Thanks, I'll have a go this evening and post up what happens.

 

So should we disable Turbo altogether or cap it?

 

Everyones welcome to there opinion the same way they choose whether or not to use your product. I have nothing against throttlestop and commend you for making it, I won't tell people not to use it either.
I base mine on long term thermal stress the same as the manufacturers will do, no one will be able to prove if either of us is correct until someone takes 2 identical laptops and pushes them to death, and repeats this to get a constant result so we have no choice other than leaving it at that. I base my decision of more than a decade of being a laptop engineer and also knowing 95% of users (fortunately people on here make up more of the final 5%) never clean a laptops fans or vents causing thermal stress the manufacturers can only estimate.

This laptop also has no cooling on the VRM's creating a hotspot (Benchmark it and watch it go over 90c on the VRM) so I would rather keep the overall temps down as much as possible due to this huge oversight on Dells part.

I think half of the problems the 45w limit on the CPU and it not wanting to snap back out of the hardware throttle.

 

Did you fix this / is it fixable / would you recommend a fix?

 

There are hundreds of posts on this.

Replace the thermal pad on the lower-left VRAM chip with a 1.5-2mm pad. All I had were 2mm ones so I just squished them with my fingers.

 

My apologies - I misunderstood. I thought GoNz0 was referring to a voltage regulator module!

I already did the VRAM repad thanks to all those threads...

 

Nothing you really can do unless you want to start packing it out to the base again. But then again we don't all benchmark all the time so I don't worry about it

 

Sorry for the confusion, are you referring to VRAM or Voltage Regulators?

Thanks!

 

regs not ram

 

Still being terrible and still throttling with BD PROCHOT disabled.

 

What are your other temperatures reading? (Gpu, ssd, etc)

 

Max on the SSD is 46°C, while the GPU stays between 75°C and 80°C under load.

GPU barely throttles as you can see in the picture.

 

What BIOS are you running? If you're updated then get that broken mobo swapped

 

So, disabling Turbo helps or na?

 

Running newest BIOS 1.20.0, also tried running the previous 1.19.0 with similar results.

Tried disabling Turbo Boost and undervolting with no result, if anything the throttling comes in earlier in this case.

 

After finding no solution to the issue I spoke to Dell who provided me with two ways forward.

1. Upgrade to advance technical support warranty?
2. Replace the entire motherboard

As I've also been having persistent issues with the WiFi card on the laptop I'm going with option two. Will let you guys know what happens.

If anyone else has been having similar issues hmu to compare temps etc..

 

Do #2. Good luck!

 

If you have HWiNFO64 installed, you can look for "PL1 Power Limit" in the monitoring page. I believe that's the power limit for non-turbo state and I've found that when throttling happens, the value could be as low as 7W, which should be 45W by default. I've never thought that this power limit could be dynamic. Maybe it's the Intel Dynamic Platform and Thermal Framework driver that does the job?

 

I have the same problem with power limit throttling while playing Dota 2 (what is the only game I played so far on my XPS 15). My CPU (i7 6700HQ) is undervolted (-150 mV) and never exceeds 75°C. Next I will try to disable the CPU turbo.

 

I had the same problem. You can see my post relating to XTU bugs and odd powerlimit throttling.

 

Keep us posted after you disable Turbo. I have to uv too, but still need more guidance on saving settings and loading XTU on start up. Everyone on here is on another level. It be nice to have a step-by-step guide on how to actually UV, save settings, and automatically start up. I need to be fed right in the mouth like a baby. Otherwise FML, RIP.

 

Read my guide in my signature.

 

Dell tech came to my place a replaced the Motherboard (and Wifi card, unrelated issue) and since then there has been no instance of Power Limit Throttling but...

...now the CPU is capped to 0.80mhz

Need to do a bit more investigation to see whats causing it but I'm edging towards asking for a complete new unit..

 

Have you tried disconnecting the battery and resetting the CMOS? I heard once this had something to do with a mobo setting about power being ticked wrongly.

 

I'll give this a go and see if anything changes.

TDP Throttling is back however. Started at 78 degrees, so a bit better but still under what it should be...

 

Are you running Intel XTU and ThrottleStop together? If so, delete XTU as those programs don't play well together and XTU has some buggy behaviour with the 9550 i5.

Also, with both XTU or ThrottleStop not running at all, can you still notice throttling at 78*C (look at Clocks on HWMonitor or similar)?

 

Get the same results when XTU or Throttlestop are or are not running.

Temperature when throttling begins is variable, just happened before at 66 degrees when playing BF4.

 

Sorry to hear that - too bad despite the new motherboard.

- Take a look at all sensors (e.g. using Aida64) as that might give you some additional insight as to where heat problem is. One of the pros here can help with more info!

- Perhaps it is an issue / incompatibility with BF4 and there is nothing you can do? It would be good to see if other BF4 players are on the 9550 and can tell you their experience.

- But one way to test if BF4 is the problem is to run some hardcore "diverse" tests (RealBench, Prime 95...) and see if you have the same temp & throttling issues. What is getting hot?

- I think you want to be running power options at High Performance here.

- As you probably know, the VRAM cooling pads are defective on the 9550 so unless you changed the pads, an overheated VRAM chip could trigger throttling quickly.

- Also people have found the thermal paste on the CPU and GPU to be poorly installed; you could fix that but I don't think that is first order issue.

- Otherwise, I suppose the replacement motherboard could have the same problem, some of the remaining hardware that was not changed has a problem, who knows...

Good luck

 

Are there still issues with this laptop? Hard to tell from the review comments, some say the 1.6GHz throttling when not on PSU was fixed in a bios update?

 

Yes it was fixed, remember we are just a few, they sold tens of thousands of these laptops.

 

You can search through the posts at notebookrevew.com to see trends in 9550 issues both in quantity and frequency. My sense is that the laptop was released last year with some bugs but most of the major issues were sorted out months ago.

Some of us have tweaked the 9550 to get a large performance boost for low cost and a bit of sweat labor; I think the average user should ignore those posts.

Regardless, the sample is tilted. Most happy 9550 users probably don't frequently post on these boards; posters tend to be people with problems (system not personal!), tweakers, and some experts who are very generous with their time and advice.

 

I uninstalled XTU, restarted my XPS and undevolted with Throttlestop. So far I only played 1 hour of Dota2 and experienced no heavy throttling to 800 MHz. Since I forgot to start the temp log I can not say for sure that their was no throttling. Maybe I will replace the VRAM pads later, first some more test need to be performed.
@pressing thanks for the hint with XTU

EDIT: I repasted the CPU and GPU, the factory pasting was really bad.

 

Xtu is garbage. It was causing throttling problems with me before as well. Doesn't even do what it's supposed to. @unclewebb alone embarrasses Intel's software dev team.

 

I have done some more testing using Aida64 and the Valley Benchmark.

The first setting was CPU + FPU + Cache stress-test using Aida64 for a bit more than 20 minutes, in the pictures between the first two white lines. Reported temps for the CPU were between 60 - 65 °C and the clock was constant at 3.1 GHz.

The second setting was Aida64 CPU stress-test + Valley Benchmark for close to 30 minutes, in the images between the third and fourth white line. The CPU and GPU temps were around 80°C. The CPU went at the beginning over 80°C with 3.1 GHz, but came down to 80°C wit 2.7 GHz after a few minutes and stayed there.

http://imgur.com/QPbinaY
http://imgur.com/dwkZ7Uo

I know that the tests were not that long and so far I have not extensively played Dota2 to test this further. But regarding that the throttling started for me after 20 minutes into the game, I feel confident that the throttling to 800 MHz is now resolved. I will let you know if anything new comes up.

 

einsteinchen - glad you have improved results. I didn't use those tests so don't know how to interpret your results but you can search through the forum to see 9550 i5 thermal ranges.

For example, my results (using the tests indicated at ambient temp of ~24*C, which don't seem unreasonable based on the posts of others follow in the post below.

For what it is worth, my results were apporox:

Prime 95 (15 minutes) 58*C
RealBench benchmark 74,141
RealBench Stress Test (15 minutes) 68*C (~2.8GHz at end of test)

 

After some research, I believe the power limit throttling we are experiencing occurs when both of the following conditions are met:
- the Intel Dynamic Platform and Thermal Framework driver is installed
- the VRM sensor reaches 100 C

On my machine at least, high CPU loads alone are not capable of pushing the VRM to 100 C. I can stress test the CPU all I want with prime95, linpack, etc. without getting throttled. My CPU temps can reach the 90s without throttling. But when both the CPU and GPU are active, like when playing a game, the VRM can reach 100 C and then throttling ensues (if the IDPTF is installed - otherwise, no throttling occurs and you can watch the VRM temp go to 105 C and beyond. Eventually, the VRM gets so hot that its current output drops, and this lack of current causes your laptop to crash.). I am pretty confident that it is only the VRM temp that is causing this throttling, because 1) the throttling appears to have no relationship with CPU/GPU temp, and 2) if you watch the graphs provided by HWInfo you see that the PL1 power limit plummets the instant that the VRM temp reaches 100 C. Furthermore, the throttling often won't solve the VRM overheating problem, because the throttling only affects the CPU, and the GPU (which is probably putting out more heat during a game and can't be undervolted AFAIK) is unthrottled. On account of the GPU, the VRM temps remain high so the PL1 power limit keeps getting lowered all the way down to 7 W.