Power statistics

Sepherosa Ziehau has been doing a lot of work with various processors states to save power on DragonFly.  He’s published a summary of how well the various P-state/C-state/mwait settings work.  He found that setting a lower C-state can perversely improve performance.

For those saying “but how do I set these lower power states?”:

sysctl machdep.mwait.CX.idle: AUTODEEP
sysctl machdep.cpu_idle_hlt: 1 (or higher)

	
Chromebook c720 results

Some time ago, I acquired a Chromebook with the help of all you kind readers.  Here’s a mini-report on how DragonFly works as a desktop.

The hardware: what I have is an Acer c720 Chromebook.  The C720p is the touchscreen model, and is equally well-supported by DragonFly.  A larger-capacity M.2 SSD (which is relatively easy to install) is the only real need, as the installed one is only 16G.  It’s easy enough to see what the laptops look like; it’s nothing fancy but it’s suitably light.

The software: There’s a wide-ranging and complete install/tweak guide for the c720 and c720p on the DragonFly site.  Note that it goes down to the point of even changing the keymap for the special keys on the keyboard.

Things I don’t like:

  • The mousepad needs a physical click, not a tap, which decreases accuracy.
  • There’s only 2G of RAM, and not expandable.  You will notice this if you tend to open a lot of tabs when web browsing.
  • I’ve had mousepad trouble, but I’m the only one reporting it, so I think it’s just bad hardware luck on my part.

Things I do like:

  • pkg is a godsend, making installation and upgrades almost effortless.  I’ve gone binary-only so far.
  • Many things Just Work – for example, the xfce4 battery plugin.
  • xscreensaver works great; even the 3D modules.  I don’t know why it entertains me so.
  • I haven’t run the battery out to make sure, but it looks like it would last a few hours.  Suspend/hibernate are not supported, but low power modes are.
  • There’s a lot of multi-touch shortcuts built into the touchpad.

It’s an excellent BSD laptop, for light use, at low cost.  The next step up would be into Thinkpad territory, which raises the cost or increases the age – and may not be as consistently supported.