Wednesday, October 6th 2021

AMD Processors Lose 15% Gaming Performance with Windows 11, L3 Cache Latency Tripled

Apparently, AMD processors officially compatible with Windows 11, exhibit a three-times increase in L3 cache latency with the new operating system. The new operating system is also found to break the "preferred cores" system on AMD processors (UEFI CPPC2), in which the two "best" CPU cores, which can sustain the highest boost frequencies, are highlighted to the operating system, so most of the light-threaded traffic could be sent to them.

AMD and Microsoft jointly made this discovery, and listed out potential impact on application performance. The increased L3 cache latency affects performance of applications sensitive to memory performance. They also warn of a 10-15% loss in gaming performance. On the other hand, a dysfunctional "preferred cores" system would mean reduced performance in light-threaded tasks as the OS is unaware which are the processor's two best cores. Thankfully, both issues can be fixed via software updates, and AMD is working with Microsoft to push fixes for both issues through Windows Update, in an update rollout scheduled within October 2021.
Source: AMD
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141 Comments on AMD Processors Lose 15% Gaming Performance with Windows 11, L3 Cache Latency Tripled

#101
chrcoluk
Windows 11 has probably had its own dev branch for a long time, probably several years, so what probably happened is when the code was implemented in Windows 10, they didnt port it over.
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#102
jpvalverde85
Maybe, just maybe, the title of the article is a bit biased, because this is not a problem within the processor, it's pretty clear that the OS is troubled. Maybe the title should be more like Microsoft botched it with Ryzen losing 15% Gaming Performance, stick with 10.
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#103
windwhirl
chrcolukWindows 11 has probably had its own dev branch for a long time, probably several years, so what probably happened is when the code was implemented in Windows 10, they didnt port it over.
Not really. I reported this issue in Feedback Hub months before Windows 11 was even speculated about.

And it had been Dev-builds exclusive bug until now
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#104
zlobby
windwhirlAnd it had been Dev-builds exclusive bug until now
It's promoted to 'feature' now. :D
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#106
windwhirl
hurakuraDo we really need Windows 11?
If you can't think of a reason why, then you don't
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#107
Chrispy_
I've not used W11 in anger that much yet but pretty much every change I've encountered is negative. Things are more obfuscated, less intuitive, require more clicks, removing popular and useful features from W10.

I can't name anything about it that I actually like.

At least with previous generations of Windows there were upsides and downsides to the interface changes but I'm really struggling to see any meaningful benefits to Windows 11's new interface. It's just worse no matter which metric you're judging it by.
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#108
ThrashZone
Hi,
Yeah ms pretty much insures people will use open shell/ .... to redo the new interface it's so bad.
Bad thing is updates will kill any third party workaround over and over.
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#109
Emily
15% is a stretch. I'm not losing that much. In fact I'm not noticing any difference from 10 to this, despite the L3 issue being indeed present in AIDA64.

Anyway, this is fixed in the latest dev channel build so I'm gonna wait until it's pushed to release.

Went back from Arch Linux to Windows 11 and I gotta say it does feel nice to have all my shit just work.
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#110
glsn
eidairaman1Yes
any quick way to install all sort of things and configs by itself? besides exporting configs and reimport them
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#111
HD64G
The reviews for AL launch will use win11 for both AMD and Intel CPUs and compare them on a broken scheduler for one of the two maybe?
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#112
B_Bang
1st Game I played on W11 jumped from Averrage 115fps to 150fps! Ryzen 5800x, 32gb 3600 c14, 5700xt... No issues with my intel wiifi eiither.... To be fair it's Diablo 3 so I'll get tback to you if I see any negatives in newer games like control...
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#113
freeagent
Its so snappy though.. and shiny. So pretty. Must touch. But yeah looks like performance is down a bit. But just chatting with you guys this thing is insanely quick.. So as a word processor, I would describe its performance as "adequate"
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#114
halo9
Darmok N JaladI’m really looking forward to Adler Lake reviews…on both Windows 10 and Windows 11. We’re going to see just how much had to be changed in software to hit performance claims, and it’s not the first time Intel’s “help” with software results in performance degradation when genuineIntel is not detected. It could quite possibly be a short-term marketing game. Early reviews will show Adler Lake looking significantly better than Ryzen on the latest and greatest Windows 11. A post-review patch from MS will come about and fix some of the glaring deficits, and only the enthusiast will know any better. Just needs to look good enough for investors to be happy and a line of commercials to air. MS gets the marketing might of Intel selling PCs with Windows 11. I can even see it being something like “only Intel 12 series CPUs are designed for Windows 11.” It all sounds like conspiracy until you look at history.
Spot on! The patch for AMD will come out after all the reviews for Intel are out which only enthusiasts will notice. Seems like a massive marketing ploy where most reviews will be done on win 11 and world media will report on this performance. Ahh well.
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#115
GURU7OF9
You have to wonder how this can be, and yet supposedly Intel have got it running perfect?

The more things change, the more they stay the same !

Big business at its best once again ! So typical !

Hopefully this is sorted very quickly, or is Windows11 really only built for Intel ?
TomorrowAs Intel is about to release Alder Lake that requires special scheduler under Win11 (that Microsoft happily obliged to build) AMD magicly loses on L3 performance before they are about to nearly double the L3 on their models.

Yeah totally no conspiracy or preferential treatmeant from Microsoft here...
You make a very good point, sounds extremely convenient timing ! Couldnt have planned it any better if you rigged it ... whats that ....?
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#116
R-T-B
I mean the fix comes out before alder lake launch if you guys would read the article. I know, that's painful, but it might break your conspiracy worries down before they begin, and that's a good thing, right?
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#117
HD64G
R-T-BI mean the fix comes out before alder lake launch if you guys would read the article. I know, that's painful, but it might break your conspiracy worries down before they begin, and that's a good thing, right?
Let's see if the reviewers will have enough time (before the reviews go online) to test both AMD and Intel CPUs properly and the fix is what it should be then...
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#118
R-T-B
HD64GLet's see if the reviewers will have enough time (before the reviews go online) to test both AMD and Intel CPUs properly and the fix is what it should be then...
It's already what it should be in dev release.
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#119
TheoneandonlyMrK
windwhirlIf you can't think of a reason why, then you don't
£#@Kin, bout the only thing I can upgrade ATM, be nice if it wasn't such a shitfest.

@R-T-B is the dev build worth a go?
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#120
R-T-B
TheoneandonlyMrK@R-T-B is the dev build worth a go?
It works well enough, but leaving dev branch is a major PITA. I'd wait for official fix.
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#121
HD64G
R-T-BIt's already what it should be in dev release.
Usually dev build features/fixes need at least 2 months to come to the normal build though and a month or so to come to the beta channel. Let's see what happens.
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#122
zlobby
TheoneandonlyMrK£#@Kin, bout the only thing I can upgrade ATM, be nice if it wasn't such a shitfest.

@R-T-B is the dev build worth a go?
Imagine if we had a perfectly working software from even its first build? While this can work only on a theoretical level that has no practical use to us, I continue to hate M$ for their cheap and sloppy implementation of pretty much everything that they make.

I mean, nobody is perfect but does this mean that they should be THAT sloppy? Sadly, yes. And the root cause is that apart from a few (relative to numbers in the entire user base) geeks in the forums, Joe and Jane have zero clue what a cache is, let alone what $L3 is, or God forbid - that it's botched by M$. Regular folks are force fed whatever dung-ridden software M$ decide to, sadly not too tech-savvy to realize it.
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#123
R-T-B
HD64GUsually dev build features/fixes need at least 2 months to come to the normal build though and a month or so to come to the beta channel. Let's see what happens.
It's been in the dev release for well over 2 months though, so even then...

Honestly I'm dumbfounded that they didn't just include it.
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#124
GURU7OF9
zlobbyImagine if we had a perfectly working software from even its first build? While this can work only on a theoretical level that has no practical use to us, I continue to hate M$ for their cheap and sloppy implementation of pretty much everything that they make.

I mean, nobody is perfect but does this mean that they should be THAT sloppy? Sadly, yes. And the root cause is that apart from a few (relative to numbers in the entire user base) geeks in the forums, Joe and Jane have zero clue what a cache is, let alone what $L3 is, or God forbid - that it's botched by M$. Regular folks are force fed whatever dung-ridden software M$ decide to, sadly not too tech-savvy to realize it.
Well I would have thought it would be much more likely to get existing known familiar hardware ie cpus working better and easier with new Win11 than an unreleased product ie alder lake?
Or is it purposefully built for Alder Lake ?
But I'm no developer!
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#125
R-T-B
GURU7OF9Or is it purposefully built for Alder Lake ?
They pretty much advertise that portions of it (like the android emu thing we have yet to see) were built with Intel in mind. I mean they even call it "Intel Bridge Technology"

I think it is safe to say Microsoft has Intel as a priority by virtue of being a larger vendor alone. Still dumb, but at least makes some amount of sense fron a purely selfish corperate standpoint.
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