XPS 15-9570, mouse/keyboard lag, repeating keys

And disable dgpu if your using an egpu

Thanks @pherrman  - if you disable that what speed does the CPU run at? Is it likely to run slow or run at full speed, and if the latter is there likely to be overheating issues?

It's interesting you say that as I'm getting DPTF error messages in the Event viewer like this:

ESIF(8.4.10501.6067) TYPE: ERROR MODULE: DPTF TIME 30916005 ms

DPTF Build Version: 8.4.10501.6067
DPTF Build Date: Feb 16 2018 13:31:38
Source File: ..\..\..\..\Sources\Policies\ConfigTdpPolicy\ConfigTdpPolicy.cpp @ line 167
Executing Function: ConfigTdpPolicy::onBindDomain
Message: ConfigTdp not supported.
Participant: TCPU [0]
Domain: PKG [0]
Policy: ConfigTDP Policy [0]

OK, so I disabled C-STATE CONTROL only in the BIOS and so far my keyboard lag and mouse stutter seem to have dissapeared. I'm not entirely happy with this as a resolution but it will do for now!

Anyone from Dell interested in this, there's clearly some issue with the CPU management!? Just for the record I have the i9 just in case it's CPU specific!

As far as I can tell C-STATE just controls the CPU when it's idle - it reduces the power consumption when there's no load on a core. Speed step on the other hand alters the speed of the processor when it is active. I've left speed step on. Disabling C-STATE appears to be reasonably safe but will increase the power used (i.e. will increase battery drain) and I guess may cause some small increase in temperature.

It runs at full speed, no problem. Also the fans are fine as well. They don't spin up. Im not sure exactly what is happening but it may help alittle. Also I have noticed that bios 1.5.0 is the most stable. So I recommend that everyone update to bios 1.7.0 and see if the problem is fixed, if not then downgrade to 1.5.0

Pete

Big thanks @pherrman, it was driving me insane. I've found just disabling c-state control appears to have done the trick for me, although I haven't tested it on my mechanical keyboard yet which was the worst. I'm on the 1.7 bios. I think the fans are running a little more but barely.

Not being able to use the keyboard and mouse was frustrating and potentially disastrous if the delete key stutters!

You've saved my bacon! 😁

I can confirm that the mouse/keyboard lag and repeating keys appears to have gone away with my home peripheral set-up even with the wired mouse/keyboard plugged into a startech dock. I had the issue both at home and at work and whether the dock was involved or not, but it was far worse with my home wired keyboard.

I've no idea why changing c-state control would fix my issue but I mention it in case it helps someone.

Just as a final test I tried turning c-state control back on in the bios and the issue returned immediately. So either c-state control is directly causing the issue or something else is causing c-state control to hiccup - maybe something is slowing the core state change so much it becomes noticeable.

Anyway hope it helps someone!

Same issue, XPS 9570 with i7-8750H. Issue happens with Dell WD15 dock and happend with HP Accelerator Shell eGPU. Sold the eGPU thinking it was the cause. Ugh.

Will try the C-State thing. Maybe it'll resolve other issues with docking as well.

Disabling C States worked for me too. However, that's not acceptable solution as it limits single core turbo boost and drains battery/using more power more in idle. And while I didn't really test this through I bet it makes forced Modern Standby battery drain even worse (yesterday my laptop was really hot after I put it out from my backpack). Really unacceptable and I really hope that Dell will fix this.

@IvanBernatovic- are you sure that disabling c-states affects turbo boost - I thought that was more to do with speed step/p-states? My limited understanding of c-states is that it saves power when CPU cores are idle by powering them down. I presume if c-states control is disabled the cores stay powered so whilst it affects battery life I wouldn't think it would affect performance!?

I'm also not the export on the topic but I ran some tests in ThrottleStop because I was trying to find out best settings for single and multicore workloads. Single thread tests behave differently with C-States enabled and disabled. If C-States are enabled I can get 4 Ghz for one core in single thread test (using ThrottleStop's integrated benchmark tool - TS Bench). If C-States are disabled when I run same single thread test my max frequency is the one that's set if all 6 cores are active. In my case that is 3.4 Ghz. I also noticed that with C-States enabled each core had unique frequency as opposed to disabled C-States where all cores were on exactly the same frequency. That suggests that multiplier is synced for all cores. Also, ThrottleStop author confirmed that here. I used HWINFO to monitor the frequencies.

It seems that disabling C-States not only prevent power saving features but also limits CPU's frequency when running single threaded or low-threaded workloads. While this is not a huge deal for me it's still very sad and unacceptable to be forced to disable C-States if I want usable experience when using USB mouse and keyboard.

I'm not only disappointed in Dell but also in big YouTubers out there who gave this laptop favorable reviews and only mentioned thermals as an issue while in reality this is far more bigger issue than thermal performance.