Mac OS X Lion host, Latest VirtualBox, Pangolin Guest 32 or 64 bit?

**mlepage** · April 26th, 2012

I've got a 2011 MacBook Air running Lion, and the latest VirtualBox. I'm looking to perform a new Ubuntu install using 12.04 (Pangolin). I'm just wondering, should I go with 32-bit or 64-bit in the guest? I know VirtualBox will do both, but I confess I still don't understand the practical issues/differences/tradeoffs.

Really I just use the Ubuntu VM for light development-type stuff (say scripting, like Lua or Python) now and then. I'm probably more concerned about battery usage than raw performance.

Advice? Is there a big page somewhere that will explain all the trade-offs to me?

**TBABill** · April 26th, 2012

If you're not giving it a huge chunk of RAM, and since you have a 4GB RAM machine I suspect you are not, it would probably be better using 32 bit in that instance.

**mlepage** · April 27th, 2012

So that's the main concern, using 64-bit if you have more RAM? (I don't on this machine, as you said.) No big differences in battery life or performance running?

**TBABill** · April 27th, 2012

I have never run Ubuntu on my MB Pro so I can't attest to it, but I've never experienced a difference in battery life on other machines based on 64 or 32 bit. If I only have 1-2GB I generally stick to 32 bit, but on machines with 3+ I stick with 64. In a VM you will dedicate part of your 4GB, which is why I figured 32 would probably work best as far as resources.

**lukeiamyourfather** · April 27th, 2012

Originally Posted by mlepage

So that's the main concern, using 64-bit if you have more RAM? (I don't on this machine, as you said.) No big differences in battery life or performance running?

If you have a 64-bit processor then use the 64-bit version. Regardless of how much memory you have or don't have the 64-bit version is significantly faster.

http://www.phoronix.com/scan.php?pag...204_3264&num=1

**mastablasta** · April 27th, 2012

64 bit should be faster on 64bit maschine. the question is is it that much faster than a 32bit? particulary if you run 32 bit applicaitons?

**lukeiamyourfather** · April 30th, 2012

Originally Posted by mastablasta

the question is is it that much faster than a 32bit?

Did you see the link comparing the two? The differences in some areas are small but are significant in others. Overall, yeah, it is that much faster.

Originally Posted by mastablasta

particulary if you run 32 bit applicaitons?

Who cares? They'll still work. Everything else that isn't 32-bit (which is pretty much everything on the system) will perform better. There's no good reason for the overwhelming majority not to use a 64-bit operating system these days.