XPS 8940, solution to freezing when idle

The one that worked for many was to set the Nvidia Control Panel 3D settings to MAX. POWER...

I assume you have an Nvidia GPU of course.

Suspect disabling anything 'going off' did the same and setting the video card to be always on?

Dell 'knew' about this problem in 2020 even, and the re-install Windows was the first response. Didn't work, they'd replace parts. SOP...

A replaced motherboard had the latest BIOS possibly, or some settings that resolved the problem. One user had gotten the last motherboard made and that had some other stuff older ones did not for the PCIe bus version for instance. Solved the problem for him.

My XPS actually has an AMD Radeon graphics card. One of things I tried after the problem came back several months after I had my motherboard replaced under my premium support contract was to update the driver from the AMD website, which had a more current version than Dell was pushing. Didn’t do anything. I had previously reinstalled windows and all my hours as part of my first support incident at the end of 2023. In the meantime, I had read about C-States and saw it, and the two sleep settings I mentioned were enabled. Disabling these settings has fixed the problem on my workstation and I just wanted to share this. I’m not saying this will work for everyone or that there aren’t other workarounds, but on the second incident I created last week, the Dell tech indicated that Dell BIOS updates can turn these on and she recommends turning them off on workstations. I’m frankly mystified that Dell hadn’t found a way to notify users as part of a service update. I imagine this will cost them some business and in my case they had to pay someone for a long trip to my house to replace a motherboard which didn’t need to be replaced. 

BTW- I had also set CPU state min/max to 100%, set power management scheme to performance, disabled all sleep settings that I could through windows, disabled all USB device sleep and also changed all graphics settings using the AMD app to eliminate sleep and use highest performance mode. None of this worked. Only the these three BIOS settings worked:

Deep Sleep

was: Enabled S4 and S5

now: Disabled

Block Sleep:

was: Unenabled

now: Enabled

C-States (under Performance)

was: Enabled

now: Unenabled

Dell BIOS updates should not change these settings, but at least two of them have in my case. Dell needs to address this, however now that I know what to look for, it's an easy fix. Still, I'm paying a lot of money for an extended premium support contract and I would have hoped I wouldn't have to figure this out myself. It looks like there are some people that have thrown up their hands on this and I'd recommend they check these BIOS settings.

Does your GPU fan start spinning real fast when it locks up? Mine does. Monitors go out, no mouse or keyboard. Have to hard reset my pc to get it back. Dell also replaced my Motherboard.

@jonfrommaine​ 

C-States (under Performance)

was: Enabled

now: Unenabled

    You do not want to disable this if you have a non-K CPU, since it only leaves C0 and C1 states active non-K CPUs need C3 for full Turbo Boost. 

S0 - On / Working

The computer is powered up. If supported, power conservation is handled by each device.

S1 - Sleep

CPU is stopped. RAM maintains power. Everything else is off, or in low power mode.

S2 - Sleep

CPU has no power. RAM maintains power. Everything else is off, or in low power mode.

S3 - Standby

CPU has no power. RAM maintains power, refreshes slowly. Power supply reduces power. This level might be referred to as “Save to RAM.” Windows enters this level when in standby.

S4 - Hibernate

Power to most hardware is shut off. Any files in memory are saved to the hard disk in a temporary file. If configured, the NIC will remain on for WOL, or AoL. This level is also known as “Save to disk.”

S5 - Off

There is not much difference between sleep and deep sleep as  S0 - S5 are the only ones Windows uses, there is an S6 but it does not apply to desktops. 

Block Sleep all this does is block the Windows sleep mode, which you can just do by editing the Windows power plan to never sleep. 

Why did I write this, just to give a little info.. If someone has a non-k CPU and makes these changes you are going to give them worse system performance.  VS just sets the GPU to prefer maximum performance, which just prevents the GPU from going into any GPU power-saving states. 

@DarrenJames​ 

To be honest, I do not recall at all. but the lock-ups/freezes almost all Nvidia card users have is that the monitor doesn't change, the mouse doesn't move, and in some cases, the sound continues as basically noise. No keys  work either.

Power OFF is the only option left to recover..

The reasoning behind the Max. Power is the thought that the Nvidia card was slow to awake as many people had the problem if the PC went to sleep (disk or monitor, or devices turned off to save power) or even the screen saver was on. Nothing woke the PC up... and would make sense if the video card couldn't update the monitor display buffer. The mouse or keyboard entry was happening, but you couldn't see it as the display buffer wasn't updated by the card.

That was basically dispelled by using the C-A-D and the strokes needed to select Reboot  which did not work.

Never get a DUMP file or anything in the Event viewer either.

However, setting the power to Max. Power has helped many. One thing to watch though, some new Nvidia drivers WILL reset that setting to default, so after ever new driver install, it pays to check the Control Panel setting.

Replace the motherboard, standard operating procedure for Dell... did it for me, and even the video card. Didn't fix it, although one used had the problem and Dell replaced his motherboard with a newer version. It apparently fixed the problem for him. You never know which one Dell puts in though. Check it against the XPS8940 FAQ. Running MSINFO32 will show you what one you have.