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I run Windows 7 in a virtual box on a Mac OS X (MacBook Pro) - but the virtual machine is pretty slow. I really hope there's a way to speed it up somehow - like reallocating memory or something? - because I plan to use Xilinx on it (it's the only reason I set up virtual box).

If it remains this slow... then it might be better to set up dual boot or a partitioned drive or something, but I originally decided against that because then I'd have to restart my computer every time I wanted to switch.

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JC: why would this be voted down? It seems to be a reasonable question... – dmonopoly Sep 21 '12 at 5:24
up vote 2 down vote accepted

First: Chech that the Guest Additions are installed properly.

After, you can try:

  • Increasing memory.
  • Using hardware virtualization if your hardware supports it (in the settings of the virtual machine, choose "Enable VT-x/AMD-V").
  • Disabling eye-candy (Aero etc...) and unneeded services in the guest operating system.

From my experience, this is what I need to do in most my VMs to get an acceptable speed.

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On a side note, having other virtualization software installed might prevent VirtualBox from using the hardware virtualization support. Mousing over the little icon that looks like a CPU with a "V" on the bottom right of the virtual machine window should show VT-x/AMD-V and nested paging enabled. – James T Sep 16 '12 at 22:32
Thanks for the advice! Definitely trying it out - and guest additions already made things much better. I'll try the other things later, too. – dmonopoly Sep 17 '12 at 6:31

Virtual machines are always slower than a host operating system. Basically your computer resources will be used by two operating systems at the same time so there's always a big performance penalty (even if you don't notice it, the computer will).

At first, you should know how much memory you can spare for Windows. For example if you have 4 GB of RAM, for Windows 7, 2 GB would be acceptable.

In my case, I have 8 GB and I run Windows 7 with 4 GB and it runs well. Although it runs much much better natively.

Also, a great idea would be storing the Virtual Machine's files on an external hard disk. It may seem awkward but it helps a lot in my case, that I have FileVault enabled! :)

Oh, by the way, have you installed Guest Additions? It helps your virtual machine to run much much smoothly (Check Devices->Install Guest Additions...).

Good luck :-)

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Thanks, this is helpful =] – dmonopoly Sep 17 '12 at 6:31

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