OpenBSD 5.9 won’t be out for a little while, but it may be helpful to plan ahead, especially since there’s been some considerable progress on hardware support. Here are some notes about what works in general and a few particular models.
5.9 will be the first release to support the graphics on Broadwell CPUs. This is anything that looks like i5-5xxx. There are a few minor quirks, but generally it works well. There’s no support for the new Skylake models, however. They’ll probably work with the VESA driver but minus suspend/resume/acceleration (just as 5.8 did with Broadwell).
The iwm driver has gotten better and along with the older iwn now supports 802.11n. Note that the three models supported by iwm (7260, 7265, and 3160) are those frequently found on Broadwell era systems. The similarly numbered 3165 (such as found on a Braswell NUC) and 8260 series found with Skylake are not supported.
UEFI boot support means systems that lack BIOS compat will work now.
Lots of fixes to USB and and xhci mean USB 3 devices should attach much more reliably.
There’s experimental support for “reduced hardware” ACPI found on some of the cheaper netbook class systems.
There’s also some very preliminary support for HID over IIC, for systems that attach keyboards and touchpads over an I2C bus.
Battery life has been getting better, though I think that’s more a function of improved hardware efficiency. OpenBSD is still missing some optimizations for low power use, but the battery life gap between OpenBSD and Windows is considerably smaller on Broadwell systems.
I’d be wary of convertibles and tablets. Touchscreen support may work, but isn’t well integrated, and the physical keyboard on such devices is often connected via unsupported interfaces.
As ever, support for Broadcom wifi and Nvidia graphics is nonexistent.
A big question is how long one might expect the battery to last while running OpenBSD. It’s not an easy question to answer.
The answer is obviously workload dependent, but even workloads are hard to quantify. The standard seems to be “wireless web” or “web productivity” or somewhat, but what does that mean? There’s considerable variation in the power demands of different web sites.
Some quick numbers from my X1, from a fairly typical (for me) afternoon. Most of the time the system is idle, as I alternately type into xterms and read code. Occasionally I pop onto the interwebs to see what’s new.
On average, I expect about 50 minutes of idle time per 10% battery. However, when pushing the processor hard, this drops precipitously. It’s pretty obvious I was blasting all four cores at 17:26.
This is after about 16 months of use, often running off battery. (The battery life of the X1 is sufficient that I rely on battery power much more than previous laptops.)
Dimming the screen makes a huge difference, especially since high resolution screens require more power to achieve comparable brightness.
Years ago, OpenBSD significantly lagged Windows in battery life. On the X1, the difference appears much less noticeable. I believe this is a combination of OpenBSD improving, but also hardware becoming much more efficient.
Even taking into account all the above, it can be hard to predetermine how well any given laptop will work. I’m trying to collect here a few recommended models.
The 2015 X1 Carbon Thinkpad works really well. Note that the 2016 model is getting a Skylake refresh. The T and X series are solid, as well. No news here for OpenBSD users. Some models of Thinkpad won’t wake from suspend unless the TPM is disabled in the BIOS.
The ASUS UX305-FA is a lightweight, fanless system. Its performance is thermally limited so it’s not workstation replacement, but works well in the “light productivity” category. The 1080p models work, the 3200x1800 models do not yet. Note that the now shipping CA model is a Skylake refresh.
Apple Macbooks generally work, but they all include dysfunctional Broadcom wireless.
Dell XPS 13 and 15. Broadwell models work with a few quirks. The new models are Skylake. The 15 looks like a good choice for a powerful desktop that’s reasonably portable. Curious to know more.
ASUS X205TA is an example of a machine with reduced hardware ACPI. Also has Broadcom wifi. I don’t know of a particularly good choice in the netbook category.
Microsoft Surface line. Sweet computers, probably not a good fit for OpenBSD at this time.