Intel chips have a massive design flaw, and both Microsoft and the Linux kernel developers are scrambling to fix it. The security hole can be patched, but the patches will make PCs (and Macs) with Intel chips slower.
We don’t know how much slowdown you’ll see yet, but one developer says a 5% slowdown will be fairly typical—at least on Linux—while certain tasks could experience slowdowns as high as 30%.
What’s Going On?
We don’t know the exact security flaw yet, as it hasn’t been publicly revealed. But we can deduce much of what’s going on from the changes being made in the Linux kernel, where development happens publicly. Microsoft is also making similar changes to Windows, which are currently active in Insider Preview builds. Apple will be forced to make similar changes to macOS, as this is a flaw in Intel CPUs.
Programs running on your computer run with different levels of security permissions. The operating system kernel—the Windows kernel or the Linux kernel, for example—has the highest level of permissions because it runs the show. Desktop programs have fewer permissions and the kernel restricts what they can do. The kernel uses the processor’s hardware features to help enforce some of these restrictions, because it’s faster to do it with hardware than software.
But Intel messed up somewhere, and the hardware that was enforcing these restrictions apparently doesn’t always work properly. So, to ensure that programs with fewer permissions can’t sneak into places they don’t belong and see things they shouldn’t, the restrictions will need to be strengthened in software (through the aforementioned patches).
AMD hardware is not affected. This change (and possible slowdown) only affects systems with Intel chips.
If you’re interested the lower level details, you should read this longer deep dive by The Register. But we won’t know the full technical details until the embargo is lifted.
How Much Slower Will My PC Be?
We don’t know how much this will affect day-to-day PC use yet. Dave Hansen, a Linux kernel developer who works at Intel, wrote that the changes being made in the Linux kernel will affect everything. According to him, most workloads are seeing a single digit slowdown, with a roughly 5% slowdown being typical. The worst case scenario was a 30% slowdown on a networking test, though, so it varies from task to task. The fix slows down system calls, so tasks with a lot of system calls, such as compiling software and running virtual machines, will likely slow down the most. But every piece of software uses some system calls.
These are numbers for Linux, so they may not apply to Windows at all. The changes being made to Windows may be different, and we may see less (or more) of a performance hit. How much this will actually end up noticeable in normal day-to-day computer use is still unclear.
We really don’t know what’s going to happen, and we won’t until the embargo is lifted and people have time to benchmark the updated versions of Windows.
But one thing is clear: Your computer is definitely not getting any faster with this patch. If you have an Intel CPU, it can only get slower.
When Will the Patch Affect My PC?
The Register expects Microsoft to publicly release this patch on the next Patch Tuesday, which is January 9, 2018. The changes will appear in an upcoming version of the Linux kernel, and we’d also expect Apple to patch macOS with similar changes fairly soon.
While a performance hit sounds bad, we strongly recommend installing these patches anyway. Operating system developers wouldn’t be making such massive changes unless this was a very bad bug with serious consequences.
Image Credit: Intel, VLADGRIN/Shutterstock.com.