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I just installed Ubuntu 13.04 (daily, full updated) and installed Windows 8 in virtualbox.
When Windows 8 is running a have huge performance issues on Ubuntu. Last week I had the same setup with Ubuntu 12.04 (full updated) and I had no problem with the overall performance.
Where is the problem and how can I fix it?
ubuntu 13.04 x64
4 GiB RAM
4x3,1 Ghz Intel Sandybridge
Windows 8 x86
1 GiB RAM
Graphics memory 128MB
Guest-extension is installed