Intel Fixes Spectre Update That Caused Reboots On Haswell, Broadwell PCs

Intel issued a microcode update for the Spectre variant 2 vulnerability for chips from the older Haswell and Broadwell generations. The company’s previous patch caused PCs using these chips to experience a high number of reboots. Eventually Microsoft had to disable the Spectre variant 2 patch on users’ machines.

New Intel Microcode Update Guidance

Intel recently released its microcode update guidance for OEMs. From it, we can now see that the Haswell series 06C3, 4066, 306F2, 40651 and 306C3, as well as the Broadwell chips series 50662, 50663, 50664, 40671, 406F1, 306D4, and 40671, have hit production. 

The chips include both the Core and Xeon variants of Intel’s CPUs, which launched in 2013 and 2014, respectively. The OEMs can now start updating those devices with the latest Intel microcode patch.

The guidance also shows that Intel is planning on updating even older CPU microarchitectures, such as Penryn, Yorkfield, Nehalem, Westmere, and Wolfdale. This could mean that Intel is prepared to fix the Spectre and Meltdown flaws going back about 10 years, considering that Penryn was first released in 2007.

It’s not clear how many existing Intel-based computers that would cover, but it’s likely to be the large majority of them. Some users may continue to use their PCs beyond 10 years, and some businesses often go longer than that.

Checking PCs For Spectre Flaws

Now that Intel seems to have a more stable Spectre v2 patch for Haswell and Broadwell users, we should start seeing motherboard firmware updates from OEMs in the next few weeks. Microsoft may also release its OS-level patches, too, in the next "Patch Tuesday" (which is two weeks from now).

There are several tools out there to verify if you’re still vulnerable to Spectre and Meltdown. Many PC users, and especially notebook users, may be surprised to see that their computers are still vulnerable to these flaws. That's because even though Intel may have issued the microcode update, the PC OEMs haven’t yet released updated firmware for devices older than the last one or two generations.

Lucian Armasu
Lucian Armasu is a Contributing Writer for Tom's Hardware US. He covers software news and the issues surrounding privacy and security.