05-18-2019 10:31 PM - edited 05-18-2019 10:33 PM
After about 20-30 minutes of using the discrete GPU for a game, I've noticed that dwm.exe and csrss.exe suddenly use a GPU quite heavily. Consequently, the game freezes and the only possible action is to quit the game completely.
The excessive GPU usage by DWM and CSRSS also occurs sometimes after rebooting the computer and waiting a few minutes.
I've seen someone else post about the same problem at https://www.reddit.com/r/thinkpad/comments/bnld6k/thinkpad_t480_gpu_and_dwmexe_help/.
What can I try doing? My laptop is covered by an active warranty if that matters.
Model: ThinkPad T480
OS: Windows 10 version 1809
Intel Graphics Drivers: 126.96.36.19972
nVidia GeForce MX150 Drivers: 188.8.131.5236
Screenshots of the GPU Activity from Process Explorer:
Context: tph.exe is a game.
08-05-2019 02:11 PM
I'm having this same issue as well. T480, MX150 discrete graphics, 32GB memory, nvme, core i7 8650. dwm.exe an csrss.exe are constantly hammering on my GPU which makes the entire machine difficult if not impossible to use. I've configured the nvidia app to prefer the discrete gpu, disabled all the power saving settings I could find and/or set to maxium performance, disabled intel speed step and do not have the lenovo vantage fan management stuff enabled. I can't tell if this is a power/temp throttling issue or something else. It seems to have happened with Windows 1809 (that's when I started noticing things running poorly). I'm now on 1903 and feel that the issue is worse. Unfortunatally, there is no way to disable the Intel UHD 620 chip on the cpu on in the bios/uefi... I feel like this is a Windows issue but on the other hand, I'm not finding much there either.
08-06-2019 06:40 AM
Here's some info on dwm. Maybe make sure you're not running any high level transparency features?
One possibility, if it isn't some sort of memory leak, is that you have some process which is somehow triggering it to want to flip to a different application--maybe an Outlook reminder, a WIndows popup notification, or anything else which is running in the background. I used to have a different box which would always crash and it turned out it was caused by a "you have new mail" popup.
I would try to make sure you manually close all of your background apps and notifications. If it always happens after a specific period of time, I would also check your power settings (i.e. if it happens after 20 minutes and you have "screen off" aftr 20 minutes, try changing it.) In theory neither of those things SHOULD cause the problem, but I've experienced similar things on other types of machines and it seems worth a shot if you haven't tried as it's an easy fix.
08-12-2019 08:34 AM
Thanks for the reply. I feel like it is some sort of software issue relating to power management of the sytem but who knows. Of note: Lenovo put a motherboard in this thing as a troubleshooting step for another problem (software issue but they love throwing parts at issues for some reason) and I decided to make sure everything was ok with the cooling system. I took the cover off and popped the fan off and noticed there was a ton of thermopaste caked everywhere so I cleaned that up and re-did the thermo paste hoping maybe I had a simple cooling issue but it didn't seem to change things much - temps went down a little bit (using open hardware monitor) but nothing substantial.
My last resort was to install 1903 from scratch and so far things seem ok. The machine got all the drivers from Windows update which was nice. I wasn't going install the Vantage app but I unded up installing it and installing everything from Lenovo except the "Lenovo Intelligent Thermal Solution" driver. So far the machine has been MUCH better. I still see GPU getting hit more than I'd expect when just sitting on idle but at least the whole machine doesn't become unusable.
I'm not saying the issue for me was the Lenovo software but for now, I'm leaving it out of my config. In terms of BIOS/UEFF settings, I've disabled any power management I could and/or set to "maxium performance". I've also created a custom power plan with everything set to always on, don't disable etc. wherever possible.
I wish I could narrow this down further but I cannot afford to continue troubleshooting this thing as I've already lost so much time from it. I've been running Lenovo's for a long time and this one has just been a real hassle for me. The TB3 dock has been miserable and then these sorts of strange performance issues have really made it hard for me to like this machine.
08-16-2019 02:18 PM
08-16-2019 02:21 PM
08-20-2019 05:37 AM
Hi, i also have T480 with 8550U and MX150. I have the same problem with iGPU. The machines runs really really bad. When there occurs a little load on the iGPU, the CPU throttles really hard, some times down to 800MHz. I have noticed that Outlook can take up 2-5% load on iGPU, and throttles down to 1.1-1.5GHz .. if i end Outlook task and iGPU load drops to 0-1%, the CPU clocks up to 2GHz instead. I have checked thermal problems, and the temperature are completely fine, only around 50c. I have also tried playing Lenovo Intelligent Thermal Solution driver by disabling it and tried undervolt, but haven't been able to fix the problem completely. To bad it's not possible to disable HD 620 iGPU.
08-20-2019 12:42 PM
TL;DR Love the machine, the form factor, etc. but I probably should have gotten a true workstation laptop
I spent a long time on this over the weekend and I've come to conclude that ultimately, I spec'd a machine that wasn't designed for any sort of virtualization/engineering type workload. What I mean by that is (and I'm no expert on CPU's and related cooling systems) is this class of machine (Ultrabook) just isn't a good fit for what I'm doing. That said, we have many of these deployed at our office with zero issue (besides the miserable tbolt3 brick docks).
It would seem (again, I'm not an expert) that:
1. Ultrabooks use processors with a very low TDP i.e. procs with a "U" at the end - 15W and they throttle back - this is great for battery life and keeping heat in check (important in an ultrabook), not so great for a heavier workload
2. use turbocharging for heavy, single-threaded processes (games maybe?) - turbocharging is fine but as soon as it goes turbo on a single thread, it either throttles because TDP or heat or both or who knows.
3. What I thought might help me may be hurting me - I thought getting the dGPU (which adds an extra cooling pipe) would help but maybe just the fact it's running generates enough extra heat to negate the benefit of the extra pipe. Unfortunatally, you cannot disable the dGPU in the BIOS.
My solution until I can get a P1 Gen 2 or newer is:
1. Enable Inhanced SpeedStep in the bios and set to max performance - I thought SpeedStep was the part of the problem; I don't think it was.
2. Install Throttlestop - undervolt the CPU (I did -101.6mV on the CPU and Cache and -60.5 on the Intel GPU)
3. Disable turbocharing (unintuative, I know)
4. set and lock TDP at 2 (this setting does NOT seem to persist on reboot)
This at least keeps everything in check. My VM's still don't run that great but perhaps there is some more tuning I can do. At this point I've wasted an obscene amount of time trying to tune around the thing that I'm embarrased about it. The bottom line is these procs are kind of neutered with a TDP of 15W - they can go up to 25 wich I believe step 4 above addresses. I'm still learning but hoepfully this gets someone down the right path.
If I'm blatently wrong on anything above, PLEASE correct me!
08-20-2019 12:49 PM
some other poings about my setup:
1. had a mobo replaced a year ago - the thremo paste was a disaster - huge globs of it everywhere - I re-pasted
2. this machine didn't really start to have issues until I installed Win 10 1809 so there is more than hardware and power at play here
3. I have Vantage installed with everything up to date including all power management utilities, display drivers etc.
4. I'm running a single 4K no zoom off a tbolt3 brick dock using mDP
5. I have the lid open so I can use Windows Hello IR and fingerprint but I have the display disabled
6. nvidia control pannel settings are all default