Virtualbox 5 - odd display resolutions without scaling

[Dest]

This might be more of a Windows host issue then guest but seeing how it effects the guests I'll post it here.

Odd thing I've noticed on my Windows 7 guests is that the display resolution the guest sees is much higher then the display resolution of the host unless I enable scaling.

Windows Host
Windows 10 (does the same thing with Windows 8 though)
Dell Precision M4800 workstation

For example, on my primary monitor my resolution is 3200x1800.
If I leave my "scaling" set at 100% on my guests, a full screen Windows 7 guest shows the screen resolution at 4267x2400
If I set the scaling at 150%, the resolution changes to 2844x1600

On my secondary monitors, the resolution is 1920x1080.
The guests see a full screen as 3840x2160


Scaling at 150%, the resolution shows at 2560x1440

In both situations the "guest display is approx 1.33 - 2x larger then actual.

The end result though is the guest dpi setting is highly tiny.

Looking in he guest logs I'm seeing that it does see the resolution:

Code: Select all

00:13:37.153742 OpenGL: Set 3D content scale factor to (10000, 10000), multiplier 10000 (rc=VINF_SUCCESS)
00:13:37.153782 OpenGL: Set OpenGL scale policy on HiDPI displays (fUnscaledHiDPI=0)
00:13:37.171491 GUI: UIMachineView::sltPerformGuestResize: Sending guest size-hint to screen 0 as 3840x2160
00:13:37.171525 VMMDev::SetVideoModeHint: got a video mode hint (3840x2160x32)@(0x0),(1;0) at 0
00:13:37.202916 Display::handleDisplayResize: uScreenId=0 pvVRAM=0000000011720000 w=3840 h=2160 bpp=32 cbLine=0x3C00 flags=0x1
00:13:37.203023 GUI: UIFrameBufferPrivate::NotifyChange: Screen=0, Origin=0x0, Size=3840x2160, Sending to async-handler
00:13:37.206078 VMMDev: Guest Log: VBoxDisp[0]: VBVA enabled
00:13:37.206127 VBVA: InfoScreen: [0] @0,0 3840x2160, line 0x3c00, BPP 32, flags 0x1
00:13:37.206207 Display::handleDisplayResize: uScreenId=0 pvVRAM=0000000011720000 w=3840 h=2160 bpp=32 cbLine=0x3C00 flags=0x1

The only other odd thing that I see is that under "View" -> "Virtual Screen 1" the max resolution there is 1920x1200. When selecting that however, the guest is re-sized and takes only approx 1/4 of the monitor.

[Dest]

Looks like i just figured it out.

The resolution that the guest sees seems to be tied to the dpi scaling of the host machine.

I had to go into the host settings and adjust the "Custom sizing options" there. the "Scale to this percentage of normal size" was set to 200%. With that set, the virtualbox resolution the guests saw was double the host.

I lowered that down to 100% and now my guest in full screen (on primary display) is 3200x1800.
On the secondary monitor, it's the correct 1920x1080.

With this in mind, the dpi scaling in the virtual machine is almost backwards the effect that the goal of this was.
If I set my scaling to say 150%, the host increases the size of text/fonts/etc 150% of normal however the virtual machine makes the visible resolution 150% greater in effect shrinking the text/fonts/etc by that amount unless the guest also has it's dpi scales accordingly

[BillG]

Beta versions have their own forum.

[smithlar]

Beta versions have their own forum.

5.0 was released early today. See the main VirtualBox web page.