Parallels virtualization: great for productivity, bad for mobility
I haven't talked too much about the MacBook Pro I bought a few weeks back as I'm simply getting my bearings in Mac OS X. Overall, I'm very impressed, but those thoughts will come out here on the blog over time. I wanted to touch upon what I think is the best...and simultaneously, the worst aspect of my initial experience and that's virtualization. Like a ton of other folks, I downloaded the trial of Parallels Desktop for Mac and was simply amazed at having my favorite Windows apps running on Vista within the Mac. There's a huge productivity gain for me as I don't have to learn new apps, but is there a price to be paid for this computing nirvana? Here's the downer for mobile users that plan to go "virtual": your battery life will greatly suffer.
I know that some of our more technically savvy readers are probably saying, "well duh, that's because you're essentially running two computers on a single set of hardware!"; yup, there's no question why the battery life is greatly reduced. My point however, is to make sure folks consider this aspect if they think a virtual machine is the answer to all of their problems. In most cases, it IS the answer, but you don't want to overlook the drain on your battery, especially if you're more mobile than sedentary.
How drastic is the drain? Let's take a look and see. I just calibrated the battery on the MacBook Pro over the weekend. I just fired up the fully charged notebook a few minutes ago and as I write this post, I have the Bluetooth off and the screen display near the minimum setting; WiFi is on and in use and the only app I've opened is my browser (currently Camino). The battery indicator shows about 3 hours and 29 minutes of juice available:
Now, lets fire up Parallels and boot into Vista. Note, I've dedicated one-half of the MacBook Pro's 2 GB of memory to the virtual machine.
Wow, the battery life just dropped to 1 hour and 30 minutes, or by nearly 57%!
Near as I can tell as a Mac n00b, the battery is getting sucked up by the additional RAM and CPU usage. Let's take a quick peek at both before and after the virtual machine starts up. Here's a shot of resources just running the Mac OS X environment and Camino:
Here's the view on the memory in use in the same situation:
Looks like with just a browser open in these conditions, the Intel Core 2 Duo can sleepwalk through the day and the battery requirements are pretty light. Now let's pop open Parallels and boot into Vista without even running any apps within Vista. Here's the CPU meter now:
And now the memory usage with Vista running in Parallels:
There's no question that running the virtual machine will eat up system resources and therefore the battery; that's a given. Just be sure not to forget that if you plan on running a virtual machine while on the run: you might be running twice as fast with two environments, but you'll only be running half as far on the same battery charge! ;)








I'm glad you're finally writing about the MacBook (you got a Pro?!!?). I didn't know this about running Vista on it. Are you really getting about 3.5 hrs of battery life in native OS X mode? Why did you pick that particular Mac browser?
Reference: OS X Web Browsers
http://mikecane.wordpress.com/2007/03/09/reference-os-x-web-browsers/
Given that Apple is rumored to come out with *MultiTouch* units later this year, I'm thinking I should skip these current MBs and go with a Samsung Q til later this year.
Posted by: Mike Cane | March 12, 2007 at 01:55 PM
Hmm... I haven't done any measurement of battery life in and out of Parallels. Though I have noticed the MBP definitely runs hotter when it's running. I wonder if XP uses less resources than Vista in a VM? I do have a Vista VM, but I mostly use XP. I don't have a good reason, other than XP is faster.
Posted by: Dave Zatz | March 12, 2007 at 04:19 PM
If the point is needing to run a couple of apps, I recommend two things:
1. Run XP and NOT Vista
2. Do not use a Bootcamp partition for Parallels, and instead use a Virtual HD. Like that you can suspend Windows when not in use, and not have to stress the hard disk booting it up each time you do need to use it. You bought a Mac to have a Mac -no need to make it a Windows powerhouse. When you want a Windows powerhouse, reboot in Windows - and wait until APple goes final with Bootcamp and provides energy saving drivers for Vista (like they have for XP)
Posted by: ebernet | March 12, 2007 at 09:50 PM
Might be fun to compare straight battery life with XP and Vista booted standalone on that machine, taking OS X and Parallels out of the equation.
Posted by: Bob | March 12, 2007 at 10:20 PM
Rubbing my hands in glee!
This is all great info! Keep it coming!
Posted by: Mike Cane | March 13, 2007 at 07:54 AM
Confirmed! Battery life indicator drops big time when my XP virtual machine is running (and as I said, heat goes up). Honestly, I only use it for Outlook (regularly) and IE (occasionally).
Posted by: Dave Zatz | March 13, 2007 at 10:33 AM
I agree on the battery life with Parallels.
Have you tried VMWare Fusion?
I run it with Vista and it is much easier on the battery than parallels. Not as good as OSX alone, but still better.
Also another tip on Vista. A Vista upgrade is a total dog. A clean install is much faster.
Try it!
Posted by: Rick | August 02, 2007 at 06:45 AM