ChromeOS is simple to use yet extremely versatile if you know how to get around, and that’s exactly why we think some of the best laptops on the market run the platform. And if you’ve paid for one of the more powerful Chromebooks available, you might be missing out on a neat feature that’s on most PCs: hyper-threading. We’ll explain here what that is, whether you’ll benefit from it, and how to turn it on.
What is hyper-threading, and why is it disabled on ChromeOS?
Hyper-threading is Intel’s proprietary take on multithreading. In short, hyper-threading takes a capable CPU core and virtually splits it into two, then facilitates the scheduling of tasks on each “core” where you effectively have more concurrent computing power. Put even more simply, it’s “divide and conquer.”
ChromeOS has supported hyper-threading (as opposed to multithreading in general), but Google opted to disable it in default setups starting with version 74 in May 2019. This was in response to a group of vulnerabilities cumulatively dubbed “ZombieLoad” (via Android Police) affecting a number of Intel CPU products that, when exploited, could allow hyper-threading to expose information that might not otherwise be visible in a user-facing way. Combined with other potential exploits, that information could be sent to malicious actors. Google did recognize, though, that many of its users relied on their Chromebooks for compute-heavy tasks, so it created a backend toggle to allow hyper-threading and make that security/performance trade-off.
The ChromeOS dev team has been working on mitigating ongoing security threats with hyper-threading. It’s also been working slowly on allowing multithreading on CPUs from other brands, but those efforts have yet to come to pass. In the meantime, Intel has long since issued “ZombieLoad” patches at various levels to its affected products.
Will I benefit from hyper-threading?
Maybe. In the consumer space, Intel only designs hyper-threading capabilities into its Core series CPU products and not its entry-level Celeron and Pentium processors — at least on the ones featured in most Chromebooks on the market. Furthermore, 12th-generation and later Core products (Alder Lake and onwards) featuring hybrid microarchitectures only have hyper-threading on the performance cores and not the efficiency ones.
This performance boost can come in handy for pretty much anything and everything you do on your Chromebook whether it’s running virtual machines or playing games. The actual metrics will depend on how many of your processing cores support hyper-threading and what application or benchmark you’re testing against, but it’s safe to say you’ll be getting an uplift somewhere in the double digits of percentage points.
If you really want to be sure about your hyper-threading situation, you can look up your processor on Intel’s online portfolio. The specifications list for each processor indicates whether hyper-threading is supported as well as how many cores (including a performance versus efficiency breakdown) and how many total threads you’ll be able to work with. Alternatively, you can install the Cog web app from the Chrome Web Store and check the CPU Usage section. If there are bars that aren’t moving around, you’ll presumably want hyper-threading turned on to activate those compute threads.
How do I turn hyper-threading on or off?
Alright, to the good part. Follow these instructions on your eligible Chromebook device:
- Open a Chrome window.
- Input chrome://flags#scheduler-configuration into the address bar and hit Enter. This will open a new window containing ChromeOS’s feature flags.
- The first feature flag should be highlighted and titled Scheduler Configuration. Click on Default, and choose Enables Hyper-Threading on relevant CPUs or Disables Hyper-Threading on relevant CPUs.
- Click Restart to effect the change.
As you enjoy your performance boost, you might want to make sure you’re ignoring other important ChromeOS settings that could do with changing.