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Window sizes changing on different monitors (not just Opus)


I'm running v12.10 on a Win10 Pro 64 bit PC. My video card is an Nvidia Quadro P2000. I have two monitors. My primary monitor is set to 2560x1440 resolution. My second monitor is set to 1920x1200.

I have a vertical two-lister layout saved that has been my primary layout for some time and has worked perfectly until yesterday. The listers are evenly divided down the middle of the screen. Until yesterday I could open it on either monitor, or drag it between monitors, and the lister adjusted to the resolution of the monitor, with the right and left listers each occupying half of the screen. But as of sometime yesterday, if I open the lister on my secondary monitor, the left side lister occupies about 2/3 of the screen and the right side lister occupies about 1/3. If I drag that list to the primary monitor it lays out perfectly with each side taking half of the screen.

I tried adjusting the layout on the secondary monitor to be evenly split, but when I drag that lister to the primary monitor, the left side takes about 1/3 and the right side takes about 2/3 of the screen.

I've tried unchecking the box "Open layout relative to the monitor the mouse is currently on" but that setting doesn't have any effect on this problem.

I've tried restoring older layout backups, with and without selecting "replace existing configuration entirely" but the problem persists.

Any suggestions would be much appreciated!


It sounds like the resolution or DPI settings on your monitors has changed.

Is the same true for other windows which cover one screen, when moved to the other? I'm guessing it will be, since Opus does not resize its windows when you move them between screens. (The OS may re-scale them, but the relative size will remain constant.)

Note that some effects of changing those resolution/DPI settings in Windows will not be seen until after a reboot. (In fact, it can take two reboots for a few things to update, which seems to be a Windows bug. But most things update on the first reboot.)


Thanks for that! You're right, it happens in other applications as well, it just wasn't as noticeable. I did not intentionally change any settings for my monitors, and when I check them in Display Settings they appear to be the same as they have always been, set to the default resolutions for those monitors.

I'm also running a Windows 10 64 in a VirtualBox VM and the problem doesn't appear there. The settings seem to be the same in both machines.

I rebooted twice, but the problem persists.

I'm guessing I should contact my hardware vendor on this one?


What are the DPI settings for each monitor?


We're a little bit over my head here ... not sure how to check DPI settings other than by checking display settings. I've attached two images of the settings for each monitor and dopus compatibility setting, but not sure if these answer your question. I'll happily dig up anything else if you can point me in the right direction.



The two monitors have different pixel dimensions and are both set to 100% DPI scaling (i.e. show everything at normal size), which means a window on one screen is always going to be a different proportion of that monitor than on the other screen.

It's like having two buckets, and moving something from one to the other: It'll have more space around it in the larger bucket.

If it wasn't like that before, you may have had the higher resolution screen set to a higher DPI scaling in the past. Do things look smaller on it than they used to?


Not that I have noticed. And, on the virtual machine guest installation, the settings are identical to the host settings I sent you, and I can move things between monitors without the problem arising. Also, when I look at the same text on the host and guest on the main monitor, it's the same size. So I don't believe the DPI scaling was ever anything but 100%.

I have another computer that has two different monitors—it's one that this computer replace about 6 months ago. On the older computer the monitors also had two different monitor resolutions, and there was no scaling there either, but again I could move apps back and forth between them without this problem.


I truly appreciate your help, and also realize that we've determined the problem isn't dopus. If you can continue to help that's great, and I won't be offended if you want me to look elsewhere, since it isn't a dopus problem.


The two monitors have physically different pixel counts (assuming they're set to their native resolutions), 2560x1440 vs 1920x1200.

That means a window which is, say 1000 pixels wide will leave 1560 pixels unused to the sides on one monitor and 920 pixels to the sides on the other monitor.

Or, to put another way, a 1900x1150 window would almost entirely cover the 1920x1200 monitor, but would have a lot of extra space around it on the 2560x1440 monitor.

Depending on the physical sizes of the screens (24", 27", etc.), the pixel densities may be different on the two screens, or it may be the same. (If it's the same, the higher res screen must be quite a lot larger than the lower-res one.) But if you're using 100% scaling on both, then the width and height of a window, in pixels, will not change when you move that window between monitors. And one monitor has a lot more pixels, so a window that is a certain number of pixels will use more of the available space on one screen than the other (as a percentage of the total space... the actual physical space it uses will depend on the screen sizes, of course).


Thanks, that makes perfect sense. The larger monitor is a 27", and the smaller 24", so they're not far apart. But I don't understand why the midpoint of the displayed contents would change. When the dopus window is full screen, shouldn't the midpoint stay in the middle?


If it's maximized, it may depend. Opus can store the midpoint as an absolute size (width of the left panel, I think), or as a percentage of the overall window size. It sounds like it's using the absolute size when you want the percentage.

Try double-clicking the splitter. I think that will reset it to 50%.


Hi Leo,

I appreciate all the help you gave me on this, and wanted to give you an update. I spent a couple hours on the phone with my PC vendor, and they were as baffled as you and I. However, I noticed today that it's working again—I can open DOpus and other apps on either screen and slide from screen to screen without the panes shifting position. It was a weird problem, I have no idea why it came up or why it fixed itself, but all is well in windows world again. Thanks again!