I recently set up a VM running Lubuntu 15.04 in VirtualBox. I can successfully run Minecraft.jar using OpenJDK Java 6 Runtime, but when it comes to playing on multiplayer servers and even singleplayer worlds, I only get 1, or very rarely 2 fps. Sometimes it even sinks down to 0 fps. I have 2 GB of RAM allocated to the machine, and I can't increase it because my host machine, Windows 10, only has 4 GB of RAM. Is there any way I can make Minecraft run faster on Lubuntu, or should I just give up and try to run it on my host machine?
There are various things that can affect the performance:
- Available RAM: 2GiB seems little, but is certainly doable when using the Optifine mod.
- Video memory: Apart from computation memory, games also need lots of video memory to store vertex buffers etc. You should be able to set the amount of video memory in the VM's settings. Also turn on 3D hardware acceleration, if available.
- Rendering method: Minecraft uses two different rendering methods: Vertex arrays, which is a bit slower, but saves on video memory, and Vertex Buffer Objects, which is faster but uses more video memory. This can be changed in Minecrafts settings at Video settings→Use VBOs. Here you can try which works better.
- Network performance: As you say it is particularly slow on multiplayer servers, this could be a network-related issue. VirtualBox uses a NAT by default, which manipulates each packet. If you change that to 'bridged adapter', the VM can directly communicate with the network adapter, which might be faster. But you may lose network connection on your host while the VM claims the adapter.
- Virtual Machine: VM's just are slower than natively running systems.
To sum it all up, I'd say that you won't ever receive a decent FPS with that configuration; VM's weren't made for gaming. Best try running Minecraft on the host system. For Windows 10, there is a native client, which I heard to be very fast.