Feed: AnandTech
Feed Link: https://www.anandtech.com
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Title: Intel Publishes First Microcode Update for Raptor Lake Stability
Issue, BIOSes Going Out Now

Date: Fri, 09 Aug 2024 15:00:00 EDT
Link: https://www.anandtech.com/show/21518/intel-pu...

Following Intel's run of financial woes and Raptor Lake chip stability
issues, the company could use some good news on a Friday. And this week
they're delivering just that, with the first version of the eagerly awaited
microcode fix for desktop Raptor Lake processors - as well as the first
detailed explanation of the underlying issue.

The new microcode release, version 0x129, is Intel's first stab at addressing
the elevated voltage issue that has seemingly been the cause of Raptor Lake
processor degradation over the past year and a half. Intel has been
investigating the issue all year, and after a slow start, in recent weeks has
begun making more significant progress, identifying what they're calling an
"elevated operating voltage" issue in high-TDP desktop Raptor Lake (13th &
14th Generation Core) chips. Back in late July the company was targeting a
mid-August release date for a microcode patch to fix (or rather, prevent) the
degradation issue, and just ahead of that deadline, Intel has begun shipping
the microcode to their motherboard partners.

Even with this new microcode, however, Intel is not done with the stability
issue. Intel is still investigating whether it's possible to improve the
stability of already-degraded processors, and the overall tone of Intel's
announcement is very much that of a beta software fix - Intel won't be
submitting this specific microcode revision for distribution via operating
system updates, for example. So even if this microcode is successful in
stopping ongoing degradation, it seems that Intel hasn't closed the book on
the issue entirely, and that the company is presumably working towards a fix
suitable for wider release.

Capping At 1.55v: Elevated Voltages Beget Elevated Voltages

So just what does the 0x129 microcode update do? In short, it caps the
voltage of affected Raptor Lake desktop chips at a still-toasty (but in spec)
1.55v. As noted in Intel's previous announcements, excessive voltages seem to
be at the cause of the issue, so capping voltages at what Intel has
determined is the proper limit should prevent future chip damage.

The company's letter to the community also outlines, for the first time, just
what is going on under the hood with degraded chips. Those chips that have
already succumbed to the issue from repeated voltage spikes have deteriorated
in such a way that the minimum voltage needed to operate the chip - Vmin -
has increased beyond Intel's original specifications. As a result, those
chips are no longer getting enough voltage to operate.

Seasoned overclockers will no doubt find that this is a familiar story, as
this is one of the ways that overclocked processors degrade over time. In
those cases - as it appears to be with the Raptor Lake issue - more voltage
is needed to keep a chip stable, particularly in workloads where the voltage
to the chip is already sagging.

And while all signs point to this degradation being irreversible (and a lot
of RMAs in Intel's future), there is a ray of hope. If Intel's analysis is
correct that degraded Raptor Lake chips can still operate properly with a
higher Vmin voltage, then there is the possibility of saving at least some of
these chips, and bringing them back to stability.

This "Vmin shift," as Intel is calling it, is the company's next
investigative target. According to the company's letter, they are aiming to
provide updates by the "end of August."

In the meantime, Intel's eager motherboard partners have already begun
releasing BIOSes with the new microcode, with ASUS and MSI even jumping the
gun and sending out BIOSes before Intel had a chance to properly announce the
microcode. Both vendors are releasing these as beta BIOSes, reflecting the
general early nature of the microcode fix itself. And while we expect most
users will want to get this microcode in place ASAP to mitigate further
damage on affected chips, it would be prudent to treat these beta BIOSes as
just that.

Along those lines, as noted earlier, Intel is only distributing the 0x129
microcode via BIOS updates at this time. This microcode will not be coming to
other systems via operating system updates. At this point we still expect
distribution via OS updates to be the end game for this fix, but for now,
Intel isn't providing a timeline or other guidance for when that might
happen. So for PC enthusiasts, at least, a BIOS update is the only way to get
it for now.

Performance Impact: Generally Nil - But Not Always

Finally, Intel's message also provides a bit of guidance on the performance
impact of the new microcode, based on their internal testing. Previously the
company has indicated that they expected no significant performance impact,
and based on their expanded testing, by and large this remains the case.
However, there are going to be some workloads that suffer from performance
regressions as a result.

So far, Intel has found a couple of workloads where they are seeing
regressions. This includes PugetBench GPU Effects Score and, on the gaming
side of matters, Hitman 3: Dartmoor. Otherwise, virtually everything else
Intel has tested, including common benchmarks like Cinebench, and major
games, are not showing performance regressions. So the overall outcome of the
fix is not quite a spotless recovery, but it's also not leading to widespread
performance losses, either.

As for AnandTech, we'll be digging into this on our own benchmark suite as
time allows. We have one more CPU launch coming up next week, so there's no
shortage of work to be done in the next few days. (Sorry, Gavin!)

Intel's Full Statement Intel is currently distributing to its OEM/ODM
partners a new microcode patch (0x129) for its Intel Core 13th/14th Gen
desktop processors which will address incorrect voltage requests to the
processor that are causing elevated operating voltage.

For all Intel Core 13th/14th Gen desktop processor users: This patch is being
distributed via BIOS update and will not be available through operating
system updates. Intel is working with its partners to ensure timely
validation and rollout of the BIOS update for systems currently in service.

Instability Analysis Update - Microcode Background and Performance
Implications

In addition to extended warranty coverage, Intel has released three
mitigations related to the instability issue - commonly experienced as
consistent application crashes and repeated hangs - to help stabilize
customer systems with Intel Core 13th and 14th gen desktop processors: Intel
default settings to avoid elevated power delivery impact to the processor
(May 2024) Microcode 0x125 to fix the eTVB issue in i9 processors (June 2024)
Microcode 0x129 to address elevated voltages (August 2024) Intel's current
analysis finds there is a significant increase to the minimum operating
voltage (Vmin) across multiple cores on affected processors due to elevated
voltages. Elevated voltage events can accumulate over time and contribute to
the increase in Vmin for the processor.

The latest microcode update (0x129) will limit voltage requests above 1.55V
as a preventative mitigation for processors not experiencing instability
symptoms. This latest microcode update will primarily improve operating
conditions for K/KF/KS processors. Intel is also confirming, based on
extensive validation, all future products will not be affected by this issue.

Intel is continuing to investigate mitigations for scenarios that can result
in Vmin shift on potentially impacted Intel Core 13th and 14th Gen desktop
processors. Intel will provide updates by end of August.

Intel's internal testing - utilizing Intel Default Settings - indicates
performance impact is within run-to-run variation (eg. 3DMark: Timespy,
WebXPRT 4, Cinebench R24, Blender 4.2.0) with a few sub-tests showing
moderate impacts (WebXPRT Online Homework; PugetBench GPU Effects Score). For
gaming workloads tested, performance has also been within run-to-run
variation (eg. Cyberpunk 2077, Shadow of the Tomb Raider, Total War:
Warhammer III - Mirrors of Madness) with one exception showing slightly more
impact (Hitman 3: Dartmoor). However, system performance is dependent on
configuration and several other factors.

For unlocked Intel Core 13th and 14th Gen desktop processors, this latest
microcode update (0x129) will not prevent users from overclocking if they so
choose. Users can disable the eTVB setting in their BIOS if they wish to push
above the 1.55V threshold. As always, Intel recommends users proceed with
caution when overclocking their desktop processors, as overclocking may void
their warranty and/or affect system health. As a general best practice, Intel
recommends customers with Intel Core 13th and 14th Gen desktop processors
utilize the Intel Default Settings.

In light of the recently announced extended warranty program, Intel is
reaffirming its confidence in its products and is committed to making sure
all customers who have or are currently experiencing instability symptoms on
their 13th and/or 14th Gen desktop processors are supported in the exchange
process. Users experiencing consistent instability symptoms should reach out
to their system manufacturer (OEM/System Integrator purchase), Intel Customer
Support (boxed processor), or place of purchase (tray processor) further
assistance.
-Intel Community Post

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