On my Macbook Pro, I found Linux used more energy running directly, than running inside a VM (tested with VMware Fusion).
So I'm happy running Linux in a VM.
This might be due to the dual GPUs (on higher end MBPs), I didn't check further after the initial battery test.
It's nicer anyway, because of the ability to run MacOS and Linux at the same time, and four-finger swipe between their desktops. That way I get the nicer GUI of MacOS, consistently good touchpad (including in Linux), and Linux for my command line dev needs, and can use utilities for either that aren't available on the other.
On an old Macbook Air, Linux might us less energy running directly rather than VM. To be sure you'd have to try both.
4GB of RAM is tight for current software, even Linux, and a VM will make it tighter. Firefox is using more than 4GB for me right now, and Safari is also using more than 4GB. So you will need to avoid using Firefox the way I do, regardless of OS :-)
You might need to stick with older versions of whatever you decide to use. I would pick one of the Linux distros that is explicitly for old machines and small memory usage.
Look into tuning TLP with a GUI if you plan on running Linux on your laptop and power usage is an issue.
> 4GB of RAM is tight for current software, even Linux, and a VM will make it tighter. Firefox is using more than 4GB for me right now, and Safari is also using more than 4GB. So you will need to avoid using Firefox the way I do, regardless of OS :-)
You can use cgroups to limit the amount of memory an application can use. I use it to limit Firefox's memory usage on a machine with much more memory than that.
MacBookPro have a driver bug that makes the dGPU run at max power (20W) whenever it is on (which is always forced whenever an external monitor is connected). So that's not why Linux uses more energy. More likely Mac is better at turning down idle services like in Safari
So I'm happy running Linux in a VM.
This might be due to the dual GPUs (on higher end MBPs), I didn't check further after the initial battery test.
It's nicer anyway, because of the ability to run MacOS and Linux at the same time, and four-finger swipe between their desktops. That way I get the nicer GUI of MacOS, consistently good touchpad (including in Linux), and Linux for my command line dev needs, and can use utilities for either that aren't available on the other.
On an old Macbook Air, Linux might us less energy running directly rather than VM. To be sure you'd have to try both.
4GB of RAM is tight for current software, even Linux, and a VM will make it tighter. Firefox is using more than 4GB for me right now, and Safari is also using more than 4GB. So you will need to avoid using Firefox the way I do, regardless of OS :-)
You might need to stick with older versions of whatever you decide to use. I would pick one of the Linux distros that is explicitly for old machines and small memory usage.