Windows 7 Guests constantly lags by running applications which use graphics acceleration

[Michel Eichelberger]

All my Windows 7 Guests (and probably Server 2008 R2 too) are lagging constantly when I run Firefox 4 or Visual Studio 2010. Windows 7 itself cause lags as well, but not that much like the other applications. Even IE9 lags more than IE8. When these lags show up, the host machine doesn't have any problems and run as smooth as when the VM doesn't lag.

When I install the Guest Additions including the experimental Direct3D-Support, the lags stop, but the Visual Studio 2010 environment doesn't render anymore, just the Window-Frame around it.

The duration of these lags ist about 10 seconds most. They show up when I run the application or switch between Tabs or close the application.

My Computer:

• Intel Core i7 2600K @ 3.4GHz (8 virtual Cores)
• Asus P8Z68 V-Pro and LucidLogix VIRTU activated
• 8 GB DDR3-1600 RAM
• 300GB WD GLFS VelociRaptor 10'000rpm
• Sapphire Radeon HD 4870 512MB

My Notebook:

• Intel Core 2 Duo T8300 @ 2.4GHz (2 Cores)
• 4 GB DDR2-800 RAM
• 250 GB HDD 7'200rpm
• nVidia GeForce 8400M GS

The lags are on both, the computer and notebook.

Settings:

Host -> Windows 7 x64 Guest -> Windows 7 x86

VBox-Settings for the VM:

• 4GB RAM allocated (on NB: 1.5GB)
• ICH9 Chipset
• IO-APIC activated
• 4 CPU-Cores (of 8) (on NB: 2 Cores)
• PAE/NX activated
• VT-x & Nested Paging activated
• 128MB Graphicsmemory
• 2D- and 3D-Acceleration activated
• ICH6 for IDE-Controller
• AHCI for SATA Controller

First I thought, that my HDD is defect because every time, when the VM lags, the HDD doesn't act anymore until the lag is over. But when I tested the settings on my notebook, I knew, that it wasn't the HDD.

I hope you could fix that, if it really is a bug or that you could help me with optimal settings for my VM, that it will run smoothly and fast. If you need more information, please ask for it as much as you need it.

(sorry for my amateur English)