VirtualBox 4.1 OpenGL 3D Guest Performance

[Panix]

These charts imply that the bottleneck is in the communication tunnel between the guest and the host. The communication overhead is large enough that it trumps any impact increased resolution may have.

For instance, LiveArena ranges between 2.2 ms/frame and 11.5 ms/frame on bare metal, and between 46.7 ms/frame and 48.5 ms/frame through the tunnel. This implies some 40+-5 ms of overhead when run through the tunnel - or some other bug in VirtualBox (4.1.2 a few months out of date, the latest version is 4.1.6).

Edit: Ah Linux guest? That's quite a bit slower than a Windows guest, because Linux guests don't get 2d acceleration and don't play well with OpenGL compositors (there are two different OpenGL compositors running, one in the guest and one on the host, which does lead to sync issues). This is what happens with two compositors: 3d in guest -> send 3d commands to host -> 3d compositor in guest -> send 3d commands to host -> 3d compositor in host -> display on screen. Disable the guest compositor and you get other problems: 3d in guest -> send 3d commands to host -> read result from host (non-accelerated!) -> display in guest -> 3d compositor in host -> display on screen.

It's going to be slow no matter what you do. For best results, you'd need to disable the host and guest compositors and implement 2d acceleration in the guest.

Wouldn't it be a more intriguing test to try PCI Express x16 VGA Passthrough? If using Intel sandy bridge architecture, to try vt-d compatible hardware w/ vt-d turned on in the bios and then test the open source games in virtualbox?

That is, if vt-d works in Vbox yet. But, I thought maybe the only way right now to get any sort of performance improvement.

I'm just asking...

Seems to me a lot has to happen for Vbox to take 'generic video card' and produce much in terms of performance when playing games......

[schmidtbag]

Wouldn't it be a more intriguing test to try PCI Express x16 VGA Passthrough? If using Intel sandy bridge architecture, to try vt-d compatible hardware w/ vt-d turned on in the bios and then test the open source games in virtualbox?

That is, if vt-d works in Vbox yet. But, I thought maybe the only way right now to get any sort of performance improvement.

I'm just asking...

Seems to me a lot has to happen for Vbox to take 'generic video card' and produce much in terms of performance when playing games......

I have already tried vga passthrough using an unused, discrete video card on an AMD IOMMU system. the gpu is recognized and can be installed but it can't be activated. i have tried everything i can think of and it still doesn't work. vga/gpu passthrough is not at all similar to regular pci, so there's more changes to be done.

[BlackStar]

I have already tried vga passthrough using an unused, discrete video card on an AMD IOMMU system. the gpu is recognized and can be installed but it can't be activated. i have tried everything i can think of and it still doesn't work. vga/gpu passthrough is not at all similar to regular pci, so there's more changes to be done.

Intriguing! I thought VirtualBox didn't support IOMMU but apparently I was wrong. Do you know which CPUs offer this capability (any chance for a Phenom 2 965BE?)

[Kano]

The CPU is not that important in case of AMD, but the chipset. Every series 9 chipset and 890FX can be used for that.

[gilboa]

As far as I remember, Xen is the only VGA pass-through capable VM platform. (As far as I can see VBox is PCI-E pass-though capable, but not VGA pass-through.)

- Gilboa