NVIDIA auto-contrast on battery issue (Precision M4700 / M6700 / M4800 / M6800 / 7510 / 7710)

Edit: Quick update / current status (2018-03-28):
This issue is reportedly resolved in the 390 series of drivers.
I confirmed this fix on 2018-06-07 with driver version 391.74.

Edit: Quick update / current status (2016-08-30):
NVIDIA says that this is caused by a power saving feature called "SmartDimmer". Additionally, the issue has been observed on the Lenovo P50 so it is not Dell specific. No solution has been found yet. NVIDIA says that any requests to change the SmartDimmer behavior will have to come from the OEM, as it is a feature specific notebook/laptop computers. Discussions with Dell to get this addressed went nowhere.

--- Original text follows ---
So, an issue has come up that makes Optimus less appealing for a while, I need the NVIDIA GPU driving everything. I switched Optimus off in the BIOS and ran into the auto-contrast on battery issue, which I will describe in a moment but has been previously discussed in the M6700 thread. I have personally encountered this issue on the M6700, M4800, and 7510 — in fact, I have never found an applicable machine that does not have this issue. I'd like to make a push to get Dell to do something about it and it would help if I can demonstrate that the issue is widespread.

Here is the issue: When running on battery, the contrast of the display changes based on the brightness of the content shown. I'm not sure what the point of this is. Strangely, the darker the image you are presenting on the display, the darker the contrast adjusts to make it. (It is not brightening up to show you something dark... it is doing the opposite.)

Prerequisites:
* You are using one of the Precision models listed in the thread title (older models may be affected as well, I do not have any to test with)
Also confirmed to affect Lenovo P50 (so probably other Lenovo systems too)
* You have an NVIDIA GPU
* Graphics switching / Optimus is disabled in the BIOS setup (NVIDIA GPU is driving the laptop display)
* You are running on battery power (AC adapter or dock is not plugged in)

Here is an easy way to check to see if your machine exhibits this problem.
* If you are running Windows 7 and you are using the "High performance" power profile, switch the power profile to "Balanced." Windows 8/10 can use any power profile.
* Unplug your AC adapter / dock to put the machine on battery power.
* Go to this page: http://stuff.aaron-kelley.net/2016/07/black2.html
* Press F11 to go to full screen mode on your browser.
* Pay close attention to the white color behind the text at the top, while you scroll the page to move the white box in and out of view. If you see the contrast level changing, this is the issue that I am talking about. You will observe that this only happens when the system is running on battery power.

If some of you wouldn't mind running this test, and posting back if you see the same issue or not. Again, every machine I have tried has demonstrated this problem. I am interested to find out how widespread it is. I guess it would also be helpful to know...
* Exactly which model Precision are you using
* What kind of display do you have
* What version of Windows and the NVIDIA driver are you running on
* Are you using the Dell Windows image or did you build your own / install from scratch

I've done some investigation on this issue and will provide some additional background / notes.

* This issue only impacts the laptop display, not external displays.

* I've done a couple of clean Windows installs just to check on this, and the issue always appears as soon as the NVIDIA driver is installed.

* This is clearly an NVIDIA driver issue. It is not an issue with the system hardware or with the screen. It was introduced when NVIDIA moved to WDDM 1.3 for Windows 8.1, but the issue occurs on all versions of Windows. This issue pops up with NVIDIA driver version 325.xx and up, but older drivers do not have it. (I believe of the machines listed in the thread title, only M4700 / M6700 are capable of running a driver old enough to escape this issue.) Also, if you are running without the NVIDIA driver loaded (safe mode perhaps), this issue does not appear.

* The issue is present in Windows "diagnostics mode" (all services and startup items disabled). It is not caused by a service or background task, but the NVIDIA driver itself.

* Myself, @win32asmguy, and @Bokeh reported this issue in the M6700 thread back in early 2014, shortly after the issue was introduced in the NVIDIA drivers.

* If you happen to be running Windows 7, you can escape this issue by going to the Windows Power Options control panel, advanced settings, and finding the setting for Display -> Adaptive Backlight. (Note: This is different than Adaptive Brightness.) Disable it and the issue will go away. This option is not presented in Windows 8 and higher. I found where the relevant settings are stored in the registry but setting them in Windows 8/10 has no effect.

* This issue is not limited to Dell machines. Here is a thread on some Asus forums complaining about the same thing. Many possible solutions are presented, and some seem to work for some people, but I've been through them all without any success. There are other threads about this problem around on the Internet but this is the most exhaustive one that I have found.

* I have attempted to engage NVIDIA directly about this issue without success. Since the issue affects the latest generation of Precision machines, it may be possible to get Dell to engage NVIDIA and get this fixed.

 

Pretty sure I've seen this on my M4800 (win 8.1 clean install). It IS annoying but thankfully I'm almost always plugged in (no Optimus =~90 minutes of battery).

I can check the Nvidia driver version later if you like.


Sent from my iPhone using Tapatalk

 

If you wouldn't mind checking to confirm that you still see the behavior and also post your NVIDIA driver version. Thanks.

 

Maximized chrome browser but I did not experience the contrast changes anywhere in menu bar, bookmark bar, tabs, or anywhere as I scrolled the white rectangle on and off the screen in chrome.

- 7710
- Windows 10
- IGZO 4k scaled 200% in windows 10 (effectively 1920x1080)
- BIOS Switchable Graphics disabled (using dGPU exclusively)
- rebooted while running only on battery
- not docked
- no external display connected
- Power Plan is High Performance

other info is in my screen captures

Perhaps it is because of something in the windows Power Plan settings? Would it help if I shared that info? Or perhaps a setting in the Color Calibration or an ICC profile? Although a profile setting shouldn't account for changes in contrast as somthing is scrolled in a browser. Does it happen in other browsers too? In other words, could it be a Chrome bug? I get tearing when scrolling in chrome but not in other browsers.





*edit:
I was mistaken. I realized my brightness levels at the time of my initial test were probably set too high for my eyes to notice any shift in brightness or contrast adjustment. I just did another test but with my display brightness lowered to half. I do see the contrast/brightness changes now, same as you guys are seeing when I scroll that rectangle box on and off the screen.

 

It is not a browser issue, it is repeatable in all browsers and even in other apps. I first noticed it in a non-browser app that popped up a dialog and dimmed the rest of the screen. I have reproduced it on a fresh Windows install with all settings at default and only the NVIDIA driver installed. I have scoured for settings to change and come up blank. It also clearly has something to do with the NVIDIA driver, as I mentioned, drivers older than 325.xx do not have the problem but once you roll around to 325.xx or later it is immediately there. It also goes away if I switch over to Intel graphics.

I wonder if it doesn't affect systems with the 4K screen (different display connection), this is the first one of those I have seen checked, all of mine are 1080p. That's part of my goal with this thread, to tease out the differences so I have a better idea of how widespread the issue is. (If it was a problem with all machines, there would be more people complaining...) Thanks for posting.

 

Sorry for the delay getting this done. I was able to confirm I have the automatic backlight adjustment, but it's very subtle, at least along the bottom of the screen brightness range. It took me a bit of work to confirm I was seeing it, but maybe I've gotten somewhat used to it?

I'm running Win 8.1 on a K2100M and 3200 x 1800 screen, driver version 347.52.

 

Thanks for checking.

I have tweaked the test to make it easier to see the issue if you enable full screen mode on your browser. The updated version is here: http://stuff.aaron-kelley.net/2016/07/black2.html

As I mentioned in the 7510 thread (where @Chiimaero also successfully reproduced this issue), I have opened my case with Dell and they are attempting to reproduce today.

 

@Aaron44126
I was mistaken. After I read Alex post I realized my brightness levels at the time of my initial test were probably set too high for my eyes to notice any shift in brightness or contrast adjustment. I just did another test but with my display brightness lowered to half. I do see the contrast/brightness changes now, same as you guys are seeing when I scroll that rectangle box on and off the screen.

Then I plugged in my ac adapter. As I was still scrolling. A couple seconds later and the contrast/brightness shifting stopped happening. So it takes a moment (a second or two) for the OS to realize I've connected the adapter and for the Nvidia driver to change it's behavior regarding that strange shift.

 

Thanks for posting. So the 4K screen is not immune. This also means 100% success rate in reproducing the issue among the users that have posted.

I notice it easily when the brightness is set to max but I guess depending on your eyes or whatever it may be easier to notice at a lower brightness level.

 

Got a response back from Dell.

It seems like they were able to reproduce the issue. However, the engineering team agreed that it is an issue with the NVIDIA driver, but since it is not a recent problem and affects all modern NVIDIA drivers, they did not feel that there was a strong enough business case to get involved with NVIDIA over this. (I guess I should have submitted my ticket back when this was first discovered...) They suggested that I could try to go to NVIDIA directly.

I will send a follow-up note expressing my disappointment (don't think it will change anything). Other avenues that I will explore are:

* Try to get NVIDIA's attention directly
* Bring this up to Dell-Mano_G next time he pops by here around refresh announcement time
* Continue to see if there is any software switch I can find to stop this behavior...