Working on a manual fix for the 50Hz unplug issue

All,

Some of us have had problems where when our systems are unplugged, the display refresh rate is uncontrollably switched to 50Hz from 60Hz. While this is a nice option to have at our disposal, many of us don't want it to occur... and as it turns out, there appears to be a particular set of conditions which lead to us being unable to turn off the switching feature by any means at all.

So I have done some investigating into the mechanisms at work when we unplug our laptops and narrowed it down to a particular registry key:

HKLM\System\CurrentControlSet\Hardware Profiles\UnitedVideo\CONTROL\VIDEO\{0C3A9C1E-8359-410F-B86F-86255E1EF2D4}\0000\DefaultSettings.VRefresh

This key is set to 50 when unplugged and 60 when plugged. The Intel Graphics Driver Service (igfxsrvc.exe) sets this value when the power conditions are changed, and later it reads this key and interprets the value, presumably switching the refresh rate as needed.

I may attempt to restrict access to the utility via permissions changes if possible, but this may not work. We'll see...

In case anyone else wants to jump in and experiment, your help is appreciated!

 

Maybe try revoking write permissions to that key for SYSTEM?

 

Oddly enough, it doesn't appear to stop the utility from changing the value. I also tried all other user groups, including CREATOR OWNER, to no avail. I actually set Deny permissions on all children as well.

What in the world? Perhaps I'm missing something in basic Registry Permissions 101 here.

 

is the key owned by TrustedInstaller?

 

Actually the Owner is Administrators.

Looks like this may in fact have something to do with these keys as well. It should be set to:

HKLM\System\CurrentControlSet\Control\GraphicsDrivers\Configuration\LEN40E20_00_07DA_95^71464BAAC35EE446D2CDFB0F8FDD32B0\00\00\VSyncFreq.Numerator = 74684609
HKLM\System\CurrentControlSet\Control\GraphicsDrivers\Configuration\LEN40E20_00_07DA_95^71464BAAC35EE446D2CDFB0F8FDD32B0\00\00\VSyncFreq.Denominator = 1246620
HKLM\System\CurrentControlSet\Control\GraphicsDrivers\Configuration\LEN40E20_00_07DA_95^71464BAAC35EE446D2CDFB0F8FDD32B0\00\00\HSyncFreq.Numerator = 47281
HKLM\System\CurrentControlSet\Control\GraphicsDrivers\Configuration\LEN40E20_00_07DA_95^71464BAAC35EE446D2CDFB0F8FDD32B0\00\00\PixelRate = 74684609

Note that the first two values (Numerator = 74684609 / Denominator = 1246620) when divided equal out to roughly 59Hz.

 

the simple fix would be to remove the app that actually does the switching.   igfxpers.exe is the culprit.

open msconfig.exe and uncheck igfxpers.exe from starting under the 'startup' tab.   reboot.   problem solved.

you could manually delete the .exe and registry key but this is the quick fix with the ability to revert back to the app running if you need it for some reason.

the reason why this didn't affect my server 2008 R2 EE SP1 installation is because i already went through the system and killed any ancillary services or apps.   i must have killed this one and forgot about it.

 

Yeah, I just disabled it using AutoRuns and found the same results and was about to post about it! You know, it's strange. Next thing I will need to check is whether this also invalidates the power management of the adapter and/or the color profiles I set. But this is most certainly helpful--goofy Intel!

 

Is it not possible to change this value from within the power saving dialog box in the Intel GMA control panel?

(I'm supposing it is not since you are going through all of this trouble, but just wanted to make sure)

 

namaiki,

The value is reset/modified automatically upon power source change.

Anyhow, yep, this also kills all custom color settings through the app, which sucks, because deepening the saturation a bit really makes the panel pop. I am experimenting with a way to make igfxsrvc.exe start once and then go away without calling igfxpers.exe, but there may be no way around this either. I wonder if it's possible at all to save the color settings as an ICC profile once they're configured and then manually apply that?

 

Or alternately, is there a way to edit the monitor's config file in Windows so it only lists 60Hz as a valid resolution?

 

That's perhaps an even better solution. Someone please let us know if you figure out such a method so that we can apply it.

If I have time, I may research that tomorrow.

For now, I am launching a small batch file upon startup which allows igfxpers.exe to do its color calibration settings and then kills it after ten seconds:

Code:

@title Intel Refresh Rate Fix - www.TripleSComputers.com
@echo Waiting to kill igfxpers.exe...
@ping -n 10 127.0.0.1>nul
@taskkill /F /IM igfxpers.exe

It works, but the problem is that should you have the adapter unplugged upon booting, the refresh rate switch still occurs.

And you know, this solution sucks, because I think it actually doesn't persist if the PC sleeps and then resumes subsequently.

Guess editing the monitor INF really would be the best solution until Intel fixes its stuff then (or if Lenovo's Power Manager is somehow switching the Intel profiles, until it's fixed)!

 

I suppose this likely has to do with the oem34.inf file (in %SYSTEMROOT%\inf ), but to be perfectly honest, I am afraid to edit it without knowing what the heck I'm doing.

 

perhaps you have something else going on here.   open the color management control panel and dump the thinkpad ICC profile.   add and manually set it to the sRGB ICM profile.   log off and back on.   see if that helps correct your saturation.

i work with graphics and photos on my X220 and haven't tweaked the intel control panel after figuring out in the first five minutes that the thinkpad ICC profile isn't compatible with the X220's LG panel.   then again, i never do any serious work on the X220 as it's simply not accurate enough for graphics.   no notebook is, really.   it's good enough in a pinch though.

 

Hey erik,

Nope, I've actually already got sRGB set. It's really no big deal, it's just that I actually like the option of pumping up the saturation a little using the Intel control panel. The fact that I can't do so without something behind the scenes swapping the profiles on me upon plug/unplug is driving me nuts!

I am beginning to wonder whether or not this might be a problem with some of the Power Management software switching graphical profiles at will in spite of the fact that it's told not to--and that perhaps Intel's drivers are just doing what they're told.

 

Can I assume that you have explored the options within the Intel Graphics Control Panel? It shows that my display is set to 50Hz when on mains power. I thought that 50Hz is the normal refresh rate for LCDs since screen flicker is not an issue (but 60Hz is there as an option).

John

 

60Hz is typical actually. It would not bother me if I did not deal regularly with video. Even watching video at a 29.97 standard fps will appear jerky with a 50Hz refresh rate. 60Hz, on the other hand, is divisible by 30, so no jerkiness appears. It's the same reason you now see televisions pushing 120/240Hz refresh rates (well, 240Hz really is sort of silly). 120Hz is divisible by 24 (the frame rate for typical film), so it's actually superior to 60Hz when viewing movies. Since I edit video on a regular basis, so it's an even bigger issue for me.

But yes, I have explored all of those options. The problem is that the refresh rate switches on its own and the profile actually changes without my consent. I have researched this and it appears to only be a problem with Lenovo notebooks--so I am wondering whether a Power Manager setting someplace behind the scenes is to blame. I wish I knew.

 

At the moment Im also experiencing this issue and no matter if I change the setting in windows, intel graphics control panel and power manager, still get the refresh rate switched to 50hz after unplugging ac adapter.

Hopefully someone can come up with a solution soon.

 

"The simple fix would be to remove the app that actually does the switching. igfxpers.exe is the culprit."

Or for testing purposes, just renaming the file or adding a number to it's name will do.

Renee

 

Yes, for now thats the only solution. I will try that when I get home today. Thanks.

 

My machine does not have this issue on a clean install. I don't have any lenovo software installed except for the fingerprint reader.

I don't know if that helps you at all, but I figured I'd chime in.

 

Some people on this thread (Alienware M14X) reported having the same issues with the refresh rate drop. According to some users on that thread, with the latest intel update, it kept the refresh rate at 60hz.

<strike>I'm trying to install the latest intel drivers, but everytime I get the error message "this driver being installed is not validated for this computer. Please obtain the appropriate driver from the computer manufacturer." Can someone tell me how can I install the latest driver without getting that error? do i need to uninstall the driver first and then install the new one? Thanks for any help provided on this.</strike>

I just uninstall the drivers and install the intel ones, and still doing the same thing. No fix with the newest intel drivers for this problem on my machine.

 

Latest off intel's site or lenovo's? I figured you were talking about Intel's site, but just checking.

I do have the latest off intel's site and I don't have the issue. Not sure if it is that or the lack of something else on a clean install. Probably worth checking out.

8.15.10.2361 is the one I have, if that helps anyone. I know my Graphics score increased by 0.1 after the update too.. hah.

 

I'm glad to see this issue getting attention and I hope that you find a good solution. FWIW, this problem existed on my T410s w/ switchable (non-Optimus) graphics about a year ago. I reported it to Lenovo through standard channels as well as through a friend that works for Lenovo as a systems programmer but to no avail. On that machine I just ran on the NVidia card all the time to avoid the issue. That worked OK but cost me some battery.

Since this machine (X220) only has an Intel card, I keep resetting it by hand when I notice that video is running poorly. I wish there was a clean solution.

FYI: I'm running a clean-install of Win7 64-bit. I was having the trouble on Win7 32-bit on the T410s.

-darren