I have a MBP, i5 CPU and 4G ram.

I run win7 using virtualbox and I allocate 2G ram for win7, only to find my Mac acts too slowly.

What can I do for that? Am I allocating too much ram?

2 Answers 2


A Mac, especially one running Snow Leopard or Lion, requires at least 2 GB of RAM for decent system performance.

Even through the system requirements for Snow Leopard are 1 GB, it doesn't perform well with 1 GB. Lion requires 2 GB of RAM just to be able to run. If you plan on running a virtual machine setup and expect decent performance from both machines, I'd have 8 GB of RAM in my machine. You can get 8 GB of ram for less than $50 from OWC.

Also, If you're not doing anything major in Windows, I'd lose the 64 bit installation, bump it down to 1 GB of RAM and try again. I use 32 bit Win7 Enterprise for work through a Parallels VM and only allocate 1 GB of RAM for it and it runs great, especially in coherence mode.

  • 1
    I agree with @Matt Love in principle but, as a matter of practice my mid-2007 MBP is maxed out at 4GB. Running a VM can take its toll on performance, but in general the computer remains useable. Of course, our expectations and your environent will differ but you might do a little digging. Maybe you're running a particularly "hungry" program (or two) on the Mac side. Maybe the problem is CPU related, not memory. (That being said, more RAM won't hurt your cause and Matt is sharing solid advice.
    – jaberg
    Jan 29, 2012 at 14:27

In addition to the more RAM suggestion from Matt, I would look at investing in a solid state disk (SSD). Generally, user experience is bottlenecked on disk input/output, and an SSD has much higher throughput. Ever since I installed an SSD in my machine I no longer have 2nd thoughts about firing a VM and slowing down my system - I see almost no performance impact.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .