Tuesday, September 6th 2016

SMT and Power Management Behind "Kaby Lake" and "ZEN" Windows 10 Restrictions

Microsoft recently sparked a stir when it was reported that the company will support upcoming CPU architectures by Intel and AMD only on Windows 10, with the keyword being "support" and not "compatibility." This means that Microsoft will offer customer-support and likely serve updates to Intel "Kaby Lake" and AMD "ZEN" machines only running Windows 10 (and its enterprise variant Windows Server 2016, based on the NT 10 kernel), and not older versions of Windows. The processors themselves are compatible with any x86 operating system, Windows or *nix, 32-bit or 64-bit. HotHardware dug out the likely causes of this decision.

Apparently, new power-management and SMT features are behind the decision. With its "Kaby Lake" microarchitecture, Intel is introducing a new power-management feature called Speed Shift Technology. This lets the processor adjust its clock-speed to match processing loads at response time of 15 ms. This likely requires OS-level hooks, so the on-die power-management components can poll for processing loads and accordingly raise or lower clock-speeds 66.66 times each second, at no CPU cost. In its ZEN microarchitecture reveal, AMD too spoke about fine-grained, multi-domain clock-gating (≠ power-gating) on its "ZEN" based processors, such as "Summit Ridge."
AMD "ZEN" processors introduce simultaneous multi-threading, a feature that exposes each physical core as two logical CPUs to the OS, for better utilization of on-die resources. Intel's implementation of SMT is the HyperThreading Technology (HTT), and has been around for over a decade. AMD's SMT implementation isn't identical to that of HyperThreading, with the two threads on a CPU competing for resources in a method unique to AMD. This can't work without the OS kernel and scheduler being aware of the method. You'll remember that Microsoft had to update the kernel and scheduler of Windows 7 in a similar way, to optimize it for "Bulldozer."

These, HotHardware argues, could be the likely reasons why Microsoft is limiting support for the new CPU microarchitectures to Windows 10. Source: HotHardware
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57 Comments on SMT and Power Management Behind "Kaby Lake" and "ZEN" Windows 10 Restrictions

#26
bug
laszlo
... point is you can't say one OS is obsolete once you still sell it....
Except MS isn't selling Win7 any longer. OEMs are.
And I wouldn't call Win7 obsolete, it's more than capable still. It's just that it's unrealistic to expect new hardware support to be added to it.
Posted on Reply
#27
Vayra86
laszlo
win7 support end 2020....


But. Windows 7 won't run any worse than advertised or than it actually was, even on the newer CPUs it will run just fine. Will it run as well as Windows 10? Probably not, but hey, that's all about the choices you make as a consumer. Not in the least because you were given a FREE opportunity to upgrade to the latest version and get these improvements for zero nada nothing, and you can't find a single OEM system sold today that has Kaby Lake/Zen ánd W7 on it, and you never will - at the same time an OEM license is tied to the motherboard, so that makes full circle right there, you can't physically have a new OEM W7 system with Kaby Lake or Zen in it and an official license.

All things considered, MS has been extremely lenient with the Windows adoption. Yes they pushed it a little, but given the disaster that was Windows XP (and the stagnation that has come with it) I can fully understand that push - even so you always had the opportunity to make a conscious choice of going back to W7 or 8. They gave away 'free' license upgrades for a full year and they support the older OS until 2020.

Now compare that to Android system support for phones, or the forced iOS and OSX updates that cripple your hardware over time and you can see how well MS is doing in the larger scheme of things. If this is MS's version of 'planned obsolescence' then I would really like more of that with other companies.
Posted on Reply
#28
cdawall
where the hell are my stars
_Flare
AMD i hope you did not make the same mistake twice !!!
There will always be a hardware and software side. AMD will probably not see crazy gains in windows based OS's for at least a generation and then it will work reasonably well. Linux OS custom built for an AMD chip? Whole different world in the same way that Piledriver and Bulldozer raped in servers up until 4th gen i series finally caught up in multithreading. They didn't surpass AMD's ability to multithread until Broadwell/Skylake.
Posted on Reply
#29
eidairaman1
The Exiled Airman
Hope theres a option to turn that off so the cpu can run full tilt at all times in bios and os. Only truly needed for laptops
Posted on Reply
#30
evernessince
Vayra86
But. Windows 7 won't run any worse than advertised or than it actually was, even on the newer CPUs it will run just fine. Will it run as well as Windows 10? Probably not, but hey, that's all about the choices you make as a consumer. Not in the least because you were given a FREE opportunity to upgrade to the latest version and get these improvements for zero nada nothing, and you can't find a single OEM system sold today that has Kaby Lake/Zen ánd W7 on it, and you never will - at the same time an OEM license is tied to the motherboard, so that makes full circle right there, you can't physically have a new OEM W7 system with Kaby Lake or Zen in it and an official license.

All things considered, MS has been extremely lenient with the Windows adoption. Yes they pushed it a little, but given the disaster that was Windows XP (and the stagnation that has come with it) I can fully understand that push - even so you always had the opportunity to make a conscious choice of going back to W7 or 8. They gave away 'free' license upgrades for a full year and they support the older OS until 2020.

Now compare that to Android system support for phones, or the forced iOS and OSX updates that cripple your hardware over time and you can see how well MS is doing in the larger scheme of things. If this is MS's version of 'planned obsolescence' then I would really like more of that with other companies.
Pushed a little? In what world is "left for work and my computer is windows 10 when I get back" or "the x button on the windows means you accept the upgrade" a little push? Don't even try to downplay that, Microsoft's upgrade tactics for windows 10 were worse than malware in most cases.

The only way one could consider windows XP is a disaster is if they are considering Microsoft's push to upgrade. In what way is Microsoft's most popular OS a bad thing? The fact that people stuck to that OS shines to it's popularity.

You know a company is ass backwards when their currently most popular OS isn't getting an update for the latest hardware. I guess that's why I see more and more people moving to linux, mac, and android.
Posted on Reply
#31
Audiophizile
evernessince
Pushed a little? In what world is "left for work and my computer is windows 10 when I get back" or "the x button on the windows means you accept the upgrade" a little push? Don't even try to downplay that, Microsoft's upgrade tactics for windows 10 were worse than malware in most cases.

The only way one could consider windows XP is a disaster is if they are considering Microsoft's push to upgrade. In what way is Microsoft's most popular OS a bad thing? The fact that people stuck to that OS shines to it's popularity.

You know a company is ass backwards when their currently most popular OS isn't getting an update for the latest hardware. I guess that's why I see more and more people moving to linux, mac, and android.
Do many companies support an over 7 year old OS? I know android doesn't. Apple stopped support on snow leopard (2009) in early 2014... So anybody wanting longer support surely aren't going to apple or android. Its kind of silly not to upgrade to a faster more secure OS especially when its free.
Posted on Reply
#32
TRWOV
_Flare
So ONE big thing of the "Bulldozer-Fail" was obviously that too much of the CPU-Management was NOT IN HARDWARE, not only that, it needed the Software of other Companies: Microsoft etc.

To not rely on the Hardware-Solutions of your own engineers, OMG.

AMD i hope you did not make the same mistake twice !!!
The OS needs to be aware of the capabilities of the processor in order to take advantage of them. When Intel introduced HT on the P4 CPUs Microsoft had to patch XP in order to take advantage of that feature and there was another patch when the Core 2 Duos (Quads?) launched. If AMDs SMT implementation is different from Intel's ad ca't be handled the same way (just as it was the case with Bulldozer) then a kernel patch is a given.
Posted on Reply
#33
ZeDestructor
eidairaman1
Hope theres a option to turn that off so the cpu can run full tilt at all times in bios and os. Only truly needed for laptops
You want it on desktops too. Sure, 20W doesn't mean much to you, but 20W over millions of people is a massive energy savings.
Posted on Reply
#34
Audiophizile
ZeDestructor
You want it on desktops too. Sure, 20W doesn't mean much to you, but 20W over millions of people is a massive energy savings.
True. Most things are becoming more power/energy efficient which is great but the enthusiast community really just wants faster. I personally don't go for a max oc but I do run a constant clock because I game and don't ever want my CPU to back down.
Posted on Reply
#35
ZeDestructor
Audiophizile
True. Most things are becoming more power/energy efficient which is great but the enthusiast community really just wants faster. I personally don't go for a max oc but I do run a constant clock because I game and don't ever want my CPU to back down.
I've had speedstep/turbo on and off over the past 4 years or so. I've seen no benefit to having my 3570K locked at 4.4GHz vs being adaptive: whenever a games spins up, it ramps straight up to max very nicely, and stays there. So I keep it on, since a lot of the time I'm in idling online or doing work rather than gaming.
Posted on Reply
#36
bug
ZeDestructor
You want it on desktops too. Sure, 20W doesn't mean much to you, but 20W over millions of people is a massive energy savings.
And it may let you turn off one more fan ;)
Posted on Reply
#37
Caring1
Audiophizile
Its kind of silly not to upgrade to a faster more secure OS especially when its free.
It's kind of silly not to support the most popular O.S. (W7) to make it faster and more secure, especially when people already bought it and like it.
Posted on Reply
#38
Ubersonic
Caring1
It's kind of silly not to support the most popular O.S. (W7) to make it faster and more secure, especially when people already bought it and like it.
If you added all the features of Windows 10 to Windows 7 then it would be Windows 10 :P
Posted on Reply
#39
Vayra86
evernessince
Pushed a little? In what world is "left for work and my computer is windows 10 when I get back" or "the x button on the windows means you accept the upgrade" a little push? Don't even try to downplay that, Microsoft's upgrade tactics for windows 10 were worse than malware in most cases.

The only way one could consider windows XP is a disaster is if they are considering Microsoft's push to upgrade. In what way is Microsoft's most popular OS a bad thing? The fact that people stuck to that OS shines to it's popularity.

You know a company is ass backwards when their currently most popular OS isn't getting an update for the latest hardware. I guess that's why I see more and more people moving to linux, mac, and android.
LOL.

And you totally didn't have the opportunity to roll back to Win 7, right? Also, it's extremely typical that these 'ninja installs' happened only on the least tech savvy of people, probably the same people who click every dialog box OK they see and then wonder why all of a sudden their 'browser is magically hacked or infected'.

Go home please. You mistake 'most popular' with downright lazy and general not-giving-a-shit PC users. If you still ran XP when Windows 10 was released, that's all it is and all it will ever be. Also, none of this changes the other facts I put forward and that you happily ignore, such as the fact that there will not be a single W7 OEM PC with Kaby Lake or Zen on it.
Posted on Reply
#40
Frick
Fishfaced Nincompoop
ZeDestructor
I've had speedstep/turbo on and off over the past 4 years or so. I've seen no benefit to having my 3570K locked at 4.4GHz vs being adaptive: whenever a games spins up, it ramps straight up to max very nicely, and stays there. So I keep it on, since a lot of the time I'm in idling online or doing work rather than gaming.
I dunno if my Win7 install was buggy, but I definitely felt a difference when disabling Speedstep (Pentium G3220). When I got an SSD it was really noticeble how things worked smoother. It works better in Windows 10 though, so I think it was a Windows 7 thing, or a driver thing.
Posted on Reply
#41
ZeDestructor
Caring1
It's kind of silly not to support the most popular O.S. (W7) to make it faster and more secure, especially when people already bought it and like it.
7 going out of mainstream support literally means that it's not getting any feature or speed improvements, only security ones. What else did you expect?

Ubersonic
If you added all the features of Windows 10 to Windows 7 then it would be Windows 10 :p
Interestingly enough, this does mean that 10 will be exactly that - lots of small features all incrementally added bit by bit. Reminds me very much of my ArchLinux rolling release install...

Vayra86
LOL.

And you totally didn't have the opportunity to roll back to Win 7, right? Also, it's extremely typical that these 'ninja installs' happened only on the least tech savvy of people, probably the same people who click every dialog box OK they see and then wonder why all of a sudden their 'browser is magically hacked or infected'.

Go home please. You mistake 'most popular' with downright lazy and general not-giving-a-shit PC users. If you still ran XP when Windows 10 was released, that's all it is and all it will ever be. Also, none of this changes the other facts I put forward and that you happily ignore, such as the fact that there will not be a single W7 OEM PC with Kaby Lake or Zen on it.
I have to concur here. Literally nobody I know had a surprise Windows 10. I will however admit that all those people had all upgraded to 10 by month 3, so there is that...

Frick
I dunno if my Win7 install was buggy, but I definitely felt a difference when disabling Speedstep (Pentium G3220). When I got an SSD it was really noticeble how things worked smoother. It works better in Windows 10 though, so I think it was a Windows 7 thing, or a driver thing.
Weird.. Could just be me having twice as much minimum on the quad-core (they run just as slow at minimum, but double the cores) on the desktop. Didn't notice anything on the laptops (HT dual-cores there as well...) though, so it could just as well be software shenanigans.
Posted on Reply
#42
bug
Caring1
It's kind of silly not to support the most popular O.S. (W7) to make it faster and more secure, especially when people already bought it and like it.
I'd like to know what's your interpretation of "end of mainstream support".
Posted on Reply
#43
Caring1
bug
I'd like to know what's your interpretation of "end of mainstream support".
Obviously not the same as Microsoft's, version, which involves a gravy train and cash flow.
Posted on Reply
#44
EarthDog
ZeDestructor
You want it on desktops too. Sure, 20W doesn't mean much to you, but 20W over millions of people is a massive energy savings.
Indeed.

Here is a tree... you know what to do... BIIIIIIIIIIIIIIIIIIIG HUGS! :)
Posted on Reply
#45
Vayra86
Caring1
Obviously not the same as Microsoft's, version, which involves a gravy train and cash flow.
Yeah it's weird that companies want to make money in our capitalist society.

I'm puzzled every day
Posted on Reply
#46
Audiophizile
Caring1
It's kind of silly not to support the most popular O.S. (W7) to make it faster and more secure, especially when people already bought it and like it.
Again, I don't know of any companies that support a 7 year old os at all. At least ms is still doing security updates. Do any companies that make more expensive software (adobe,etc.) support their 7 year old versions? Most electronics cost more than a copy of windows and lose support much sooner than 7 years. Complaining they aren't making speed updates on anything tech related that's over 7 years is definitely silly.
Posted on Reply
#47
bug
Caring1
Obviously not the same as Microsoft's, version, which involves a gravy train and cash flow.
I'd still like to know.
Posted on Reply
#48
Caring1
bug
I'd still like to know.
It's irrelevant, as it's not my decision to end support.
Posted on Reply
#49
bug
Audiophizile
Again, I don't know of any companies that support a 7 year old os at all. At least ms is still doing security updates. Do any companies that make more expensive software (adobe,etc.) support their 7 year old versions? Most electronics cost more than a copy of windows and lose support much sooner than 7 years. Complaining they aren't making speed updates on anything tech related that's over 7 years is definitely silly.
RHEL gets like 10 years of support. But that's an enterprise product and even that doesn't get support for newer CPU architectures. I think RHEL5 is stuck somewhere at Haswell.
Posted on Reply
#50
BlueFalcon
laszlo
why? - is another way to force implementation of win10....
Every launch of the next version of Windows is always accompanied by hate and negativity surrounding it, while these same users start defending the older version of Windows as the best ever! Not only does Windows 10 combine all the best features of Windows 7 and 8.1, but it also runs, boots, restarts, goes to sleep and wakes up faster than either Windows 7 or 8/8.1. On top of it, it has extra perks such as DX12 gaming support, ability to more freely multi-task seamlessly (multiple desktops, 4 separate quadrants on the screen, run 2 excel files side-by-side, etc.), and performs faster on slower systems than either Windows 7 or 8/8.1. Additionally, the upgrade was offered for free for an entire year. It's actually still possible to get the upgrade using Windows Assistive Technologies. I've used Windows 95, 98, XP, Vista, 7, 8, 8.1 and now 10 and W10 is the best Windows yet. Considering Windows 10 is going to be incrementally updated by MS over the next 5+ years, or even more, it makes no sense to stick to old Windows 7-8.1 versions for someone building a new system in 2016-2017.
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