Quote:Now, a major Hyper-Threading flaw has been discovered that can destabilize Intel CPUs based on both Kaby Lake and Skylake — not something Intel needed on the heels of AMD’s new CPUs. The issue is reported to cause “unpredictable system behavior,” which could mean anything from corrupting data to outright system crashes. The issue was picked up by Hot Hardware, via Debian.org. While Debian is a Linux distro, the warning makes it clear that the problem can happen to any operating system and is not limited to Linux.
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Intel has apparently issued microcode updates for Skylake and Kaby Lake processors to address this problem, but they’ll need to be integrated into motherboard UEFI to work effectively. We recommend checking for board updates to see if there’s an update available if you’re using a Skylake or Kaby Lake chip.

For the record, while ExtremeTech believes Intel that these errata exist, we are not aware of any software programs affected by them and have not observed any issues with our Skylake or Kaby Lake testbeds. Our Core i7-7700K and Core i7-6700K both performed flawlessly when tested in our benchmark suites over the past six months.

If you’re having a specific problem with a piece of software that cropped up once you moved to Kaby Lake or Skylake, we recommend shutting off Hyper-Threading and seeing if that resolves the problem. Hopefully motherboard manufacturers will have solutions ready to go sooner rather than later.

Quote:Update, 6/27/17, 12:00pm PT: Intel responded to our questions with the following:
“We have already identified this issue and addressed it with a fix that started rolling out in April 2017. As always, we recommend checking to make sure your BIOS is up to date, but the chance of encountering this issue is low, as it requires a complex number of concurrent micro-architectural conditions to reproduce.”