Question about guest's display settings

[NA!]

I have a WinXP SP3 guest. 2 monitors on the host which have been passed in the guest too, with 1920x1080 each. No 3D acceleration selected (not in the guest settings but also the 3D driver is not even installed).

VBox lets me assign only up to 128 MB videoram for this guest VM. I assume that's why in the guest, i can select the primary monitor to have 32-bit color but the secondary only up to 24-bit. Is that indeed the case or this is a limitation of the OS?

I'm using seamless mode with host toolbars on top, so the actual guest resolutions are 1920x1018 for primary monitor and 1920x1050 for the secondary.

On a sidenote, this is a development VM. Would anyone recommend the installation and use of 3D acceleration in the guest? Not really needed by any app i use in the guest, but if this will increase quality/speed/stability or anything else...

[mpack]

I assume that's why in the guest, i can select the primary monitor to have 32-bit color but the secondary only up to 24-bit. Is that indeed the case or this is a limitation of the OS?

I doubt that is correct. The restriction would be that you have to use the same video mode as the host, especially if you want to use something like seamless mode. Hence, I suspect one of your host video cards is set for 32bit, and the other is set for 24bit.

A 1920x1080x32bpp frame requires 8.3MB for storage. So, 128MB allows for 16 such frames to be buffered in "graphics RAM". Marginal I'd say.

I'm surprised when you say that you aren't allowed to configure 256MB. It's my understanding that configuring two monitors is how the 256MB option is enabled. But, I just tried it and I couldn't do it either. Modifying the .vbox file manually did work. Enabling 3D acceleration also allowed 256MB, even with one monitor.

On the latter subject: my personal experience is that enabling 3D acceleration makes some things faster (especially 3D of course). It also creates many stability problems for some users, since it relies greatly on host OpenGL drivers being bug free. Nobody can say if it will work for you: back up your VM and try it.

[NA!]

I doubt that is correct. The restriction would be that you have to use the same video mode as the host, especially if you want to use something like seamless mode. Hence, I suspect one of your host video cards is set for 32bit, and the other is set for 24bit.

Nope, i don't think so. The host is Win7SP1 and in Display settings, the color-depth does not appear. I checked in advanced settings each monitor and both are set to 32-bit. As a sidenote, i have one videocard only (laptop), a builtin display and an external monitor.

I'm surprised when you say that you aren't allowed to configure 256MB. It's my understanding that configuring two monitors is how the 256MB option is enabled. But, I just tried it and I couldn't do it either. Modifying the .vbox file manually did work. Enabling 3D acceleration also allowed 256MB, even with one monitor.

So, should this be considered a bug?

On the latter subject: my personal experience is that enabling 3D acceleration makes some things faster (especially 3D of course). It also creates many stability problems for some users, since it relies greatly on host OpenGL drivers being bug free. Nobody can say if it will work for you: back up your VM and try it.

Thanks for the input. From what you say i believe that my decision not to enable 3D all this time was probably correct. I'll think i'll stick to how are thing now and perhaps reconsider enabling 3D some time in the future.

[mpack]

So, should this be considered a bug?

Sure, if you can find somewhere in the docs that describes it doing something else. Otherwise not.