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HankDeVreece
Fanfold Paper
Posts: 6
Registered: ‎09-14-2019
Location: NL
Views: 1,532
Message 1 of 20

P1 Gen 2 power limit throttling

Hi all,

 

Got my Thinkpad P1 Gen 2 three weeks ago. Really nice machine! However, its thermal policy seems unfinished to me and unnecessarily holds back the laptop. I also put in a support request in the Netherlands but I was told that all they could do was fix hardware issues; they offered to replace the motherboard but I said that would be a waste and instead asked them to escalate the issue to the team that actually looks at these things. The agent said he'd do that, but it doesn't hurt to give this a shot as well. And perhaps other people have something to contribute as well.

 

So, long story short: this laptop has powerful components that generally perform well but not as well as one expects. To keep the laptop cool and quiet Lenovo seems to have implemented dynamic power limits which, depending on the situation, can strongly reduce performance. And I get it, this is quite a thin and light machine, there are limits to what the cooling can do etc. But what I don't get is that quite conservative power limits are enforced (in an illogical way) when the laptop is in maximum performance mode, isn't very warm and when the fans don't actually spin at their maximum (and don't come close to it). This is marketed as a mobile workstation!

 

What I noticed is as follows:

  • Not very dynamic, but the Nvidia GPU (a Quadro T1000 in my case) has a power limit of 35W on mains (30W on battery).
    This is below the 40-50W TDP that Nvidia specifies for it. Under heavy real-world usage 35W isn't enough for the GPU to sustain its maximum clock speed, which can be reduced by about 10%. This when it isn't at all hot (63°C when using the GPU alone; 74°C when taxing the CPU as well) and the fans are only spinning lightly to moderately. Increasing the power limit to 40W should eliminate this kind of throttling.
  • There is a combined CPU + Nvidia GPU power limit of 65W, and this isn't enforced in a very smart way.
    When the Nvidia GPU is under some load, the CPU's long-term power limit (PL1) is reduced to 30W. This is also the case if the load on the Nvidia GPU is rather light and combined power draw doesn't come close to 65W. Additionally, the laptop comes with a 135W power brick and it shouldn't be a problem to deliver more than 65W to those components. Again, the parts aren't particularly hot and the fans don't spin very hard.
  • The CPU's long-term power limit (PL1) oscillates when the Nvidia GPU is active.
    When both are active and the CPU is heavily stressed, instead of having the fans spin at a constant rate and CPU's PL1 settling at a constant number, the PL1 oscillates between as low as 15W and as high as 45W, with the fans slowing down or speeding up according to the heat production that comes with it. This on itself undesired behaviour but the worst is that the CPU's performance is reduced much further than necessary (15W?!).

Again, I get that there are limits to the performance one can expect from a rather thin and light chassis. But what happens now just seems arbitrary and badly implemented or tested. I am not anywhere near the thermal limits of the platform, this is just weird policy. When ONLY the CPU is in use, things are fine. But whenever the GPU is active (whether under load or not) the CPU's power limit goes wonky, and the GPU itself is arbitrarily constrained at too low a power limit. Please let Lenovo fix this so that full performance can be had when desired.

alexcherney
Fanfold Paper
Posts: 8
Registered: ‎09-19-2019
Location: AU
Views: 1,380
Message 2 of 20

Re: P1 Gen 2 power limit throttling

I have the same issue with P1 Gen2 i7-9850H and T2000. The system is very slow when both CPU and GPU are in use (rendering Adobe Premiere).

If I disable the T2000 GPU in the device manager and reboot then it renders faster! Look like the laptop is not usable for the purpose I bought it for and I will have to consider returning it.
alexcherney
Fanfold Paper
Posts: 8
Registered: ‎09-19-2019
Location: AU
Views: 1,347
Message 3 of 20

Re: P1 Gen 2 power limit throttling

Here are my HWMonitor Screenshots

 

1. Rendering in Adobe Premiere with GPU and running Cinebench for CPU load:

CPU throttled to just 12W TDP with 100% utilisation. Temps around 60C

 

CPU_GPU.PNGCPU+GPU

 

2. CPU Only with Cinebench R15 - expected 45W TDP.
CPUONLY.pngCPU Only

ve2mrx
Token Ring
Posts: 139
Registered: ‎07-07-2019
Location: CA
Views: 1,279
Message 4 of 20

Re: P1 Gen 2 power limit throttling

Hi alexcherney,

I have one question, and one remark:

- When you refer to TDP, do you refer to Thermal Design Power? The continuous power a package was designed to work at?

I'm asking because in your #2 screen capture, the CPU package indicates ~45W in the Value and Max columns. Instrumentation in computers is not perfect, so 44.8W really is 45W.

I am surprised however at your #1 screen capture showing 100% CPU, ~15W package power, and only 60C temperature.

Ensure your BIOS and Embedded Controller (EC) are up to date, they manage the fans and power settings. Post their versions back here.

I would suggest you monitor your CPU with Intel eXtreme Tuning Utility, that would show more details at what the CPU is actually going through. I DO NOT recommend changing any settings for the CPU in XTU, only using the Monitor feature. If you change settings, you mess with the troubleshooting process at hand. In XTU, check if any throttling occurs, and which types (if any).

Unfortunately, I have a P52, not a P1, so my results are not comparable.

Martin
I'm a user, NOT a Lenovo employee. If my post helped, consider giving me a Kudos. If I solved your issue, please mark it as Solved.
P52 I7-8750H P1000 FHD 16GB 512GB-SSD 1TB-HDD
alexcherney
Fanfold Paper
Posts: 8
Registered: ‎09-19-2019
Location: AU
Views: 1,255
Message 5 of 20

Re: P1 Gen 2 power limit throttling

Hi Martin

Thanks for looking. 

 


@ve2mrx 
- When you refer to TDP, do you refer to Thermal Design Power? The continuous power a package was designed to work at?

I'm referring to the CPU Package Power

 

I am surprised however at your #1 screen capture showing 100% CPU, ~15W package power, and only 60C temperature.

So am I - surprised and dissappointed. This behaviour only happens when both NVidia GPU and CPU are under load. The easy way to reproduce is to run CineBench R20 and OctaneBench together for a few minutes - it begins with 45W CPU Package power, then drops to 15W and stays there with temperatures only around 60C.

 

Ensure your BIOS and Embedded Controller (EC) are up to date, they manage the fans and power settings. Post their versions back here.

Done that already. Lenovo Vantage reports all is updated, I also checked online - the BIOS installed is the newest version - 1.25.

 

Unfortunately, I have a P52, not a P1, so my results are not comparable.

Still would be interesting to see what your temperatures and power are when running Cinebench and OctaneBench at the same time

I am not usually running benchmarks on my hardware but I noticed that the Premiere render times were considerably slower than I expected and started to investigate.

 

Considering that it is not an isolated incident, I believe Lenovo engineers can fix this behaviour in a BIOS update and would be prepared to wait and beta test the BIOS update if Lenoveo commits to fixing it. However I am still withing the 30 day return period for another 2.5 weeks and am tempted to just return it get a replacement from another manufacturer that is not crippled by thermal throttling.

 

Cheers,
Alex

alexcherney
Fanfold Paper
Posts: 8
Registered: ‎09-19-2019
Location: AU
Views: 1,228
Message 6 of 20

Re: P1 Gen 2 power limit throttling

A real world scenario from today - converting imags from Canon RAW (.CR2) to JPEG in Adobe Bridge using both CPU and GPU. CPU utilisation - 100%, Power - 15W only, Core Clock 1995 MHz temperature 65C! Painfully slow for 1500 files... 

 

 

tycruickshank
Paper Tape
Posts: 1
Registered: ‎09-23-2019
Location: US
Views: 1,136
Message 7 of 20

Re: P1 Gen 2 power limit throttling

I thought I would chime in here because I have a Dell Precision 5530 (nearly identical to the XPS 15 (9570) except for quadro graphics (p2000) and my machine exhibits the exact same behaviour that you are describing. If the GPU is active much at all the CPU gets incredibly downclocked and it's incredibly annoying. Perhaps this isn't a problem that is specific to Lenovo. I've been trying to find a solution, but I haven't found anything that is useful.

 

I also have a 15" MacBook Pro from 2016 (first touchbar version) and if I do the same test (GPU load + cpu load) in Windows 10 Pro (version 1903, same with the Precision 5530)  the CPU does not downclock all the way to 800 mhz like I'm seeing with my Dell. Even with a full synthetic load on both, the GPU stays at 100% and the CPU holds pretty steady around 2 ghz (below base clock, but what do you expect when running full load on GPU + CPU). The GPU in that machine doesn't draw as much power as far as I'm aware so perhaps that is the cause. There is also no graphics switching when running Windows on a Mac so I wonder if that has something to do with it?

spocko
SCSI Port
Posts: 42
Registered: ‎10-11-2018
Location: US
Views: 1,130
Message 8 of 20

Re: P1 Gen 2 power limit throttling

P1 G1 seems to perform similarly. When running Cinebench R20 and OctoBench 4 simultaneously, the CPU package power drops as low as 15W, ~ 1.8 GHz, temps in the 70's. It doesn't stay at that minimum power very long, it seems to rebound to about 20W.

 

If I run CB 20 by itself, the CPU package power doesn't drop below about 37W.

 

Overall the system seems to sacrifice CPU performance in favor of GPU performance.

HankDeVreece
Fanfold Paper
Posts: 6
Registered: ‎09-14-2019
Location: NL
Views: 842
Message 9 of 20

Re: P1 Gen 2 power limit throttling

Never had time to post again here. Good to see others making some noise too. I just noticed that Lenovo issued BIOS 1.26 a few days ago with the exciting note "Improve Thermal control policy for better performance". Did anyone try it out yet?

alexcherney
Fanfold Paper
Posts: 8
Registered: ‎09-19-2019
Location: AU
Views: 832
Message 10 of 20

Re: P1 Gen 2 power limit throttling

I've been testing BIOS 1.26 for two days now and so far the results are very encouraging. Almost no power limit throttling with CineBench R20 and I am getting great scores: just over 2700 (!) with moderate 100 mV undervolting.

 

When I run it with Octane at the same time it still throttles but less agressively - around 30W CPU Power and 75-80C temperature (Cinebench scores are above 2000 when Octane is running in parallel). More importantly though, when rendering in Premiere with the GPU, the CPU temperature now stays above 90C with very little throttling.

 

So overall - very happy with the update. It could still do a bit less restrictive throttle when GPU is in use, but it seems to resolve most of the thermal throttle issues.  

 

Note that I needed to power off and power back on after the BIOS update before the thermal issues went away.

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