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Intel to shut down renegade Skylake overclocking with microcode update

158 points| pavornyoh | 10 years ago |arstechnica.com | reply

127 comments

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[+] xlayn|10 years ago|reply
There are two things for this situation

  -On one hand Intel is disabling a "Feature" of their cpus
   as a way of preventing users to get "More expensive 
   performance" without paying for it; you can think of it
   like intel is just covering their back; we can assume the
   difference on their cpus is just related to binning [0]
   and they are just protecting their customers by not 
   allowing less performant cpus perform better therefore 
   increasing reliability.
  -on the other hand you can see how hardware is not
   anymore something you buy and expect to behave in a
   certain way.
   For those paranoid... would this mean they can also alter
   how instructions behave? **cough**security**cough**
[0] https://en.wikipedia.org/wiki/Product_binning
[+] andromeduck|10 years ago|reply
Yes microcode can alter the way instructions behave and it's been like this for a decade.

What worries me more is something like Nvidia's Denver architecture because that's actually a full abstraction above machine code.

[+] awqrre|10 years ago|reply
All computing in general is somewhat broken if you are looking for absolute security (broken by design)... I wish that I see a solution to this in my lifetime...
[+] makomk|10 years ago|reply
Are Intel still disabling random features in the K versions of their processors for market segmentation reasons? Figuring out what processors had what features locked off was getting truly ridiculous.
[+] flyinghamster|10 years ago|reply
One thing I've really hated about Intel in recent times has been that you can't really tell what you're getting based on the model number.

I got bitten by this when I built up a system and picked a Core 2 Quad Q8200, only to discover after powering it on that it did NOT have virtualization support.

The problem is only worse now; is that i7-xxxx dual-core or quad-core? Should I get i5-yyyy instead?

[+] roddux|10 years ago|reply
What possible reason could they have for this, apart from forcing users to buy their 'unlocked' chips? Is it really worth the nightmarish PR debacle they will undoubtedly face?

Side note (from comments) -- apparently Intel paired this microcode update with a patch to fix CPUs freezing during Prime95. Not cool.

[+] revanx_|10 years ago|reply
What nigtmarish PR are you talking about? Nobody cares, just like nobody cared when they started shipping cpus with embedded Intel ME.
[+] deckar01|10 years ago|reply
The irony is that if you are running Prime95 and overclocking, Intel should love you, because you are going to be in the market for a new processor much sooner than the average user.

Prime95 slowly cooked several PCs that I had the pleasure of supporting through my years in college.

I love what Prime95 wants to do, but consumer PCs are not usually designed/maintained with 100% CPU usage in mind.

[+] tspiteri|10 years ago|reply
Overclocked CPUs run hotter. For modern technologies that means they can degrade faster, and can fail earlier than their expected lifetime. To be clear, I'm not saying this is the reason Intel did this, but it is one possible reason, and you asked for possible reasons.
[+] snvzz|10 years ago|reply
I'm glad they're doing this. It'll help plant an image: Proprietary microcode is evil.
[+] astrodust|10 years ago|reply
The alternative here is what, exactly? Can you site an example of a better situation?
[+] alkonaut|10 years ago|reply
Can't they just disable it for yet unsold cpu:s (e.g. look at serial numbers or something)? Consumers (should) only care if their product is made worse after they purchased it. I can see why someone would be angry if a feature that was advertised is removed after the purchase.
[+] Klathmon|10 years ago|reply
IMO this would only be an issue if they advertised that it was overclockable.

If it was advertised with no ability to overclock, you should assume it can't overclock and if you are able, don't assume it will work or will stick around forever.

[+] wbkang|10 years ago|reply
Pretty sure the microcode update is applied on every boot both by the mobo and the operating system.
[+] userbinator|10 years ago|reply
Those supporting AMD should remember that they did a similar thing after it was discovered that some processors could have entire cores re-enabled.

On the other hand, if I remember correctly one of the mobo makers soon figured out how to use both the new microcode and the old one to get the best of both worlds; it might've been AsRock too...

[+] Already__Taken|10 years ago|reply
Those supposedly triple and dual core CPUs that got unlocked to quad cores were apparently a way to sell damaged silicon that the remaining cores passed QA so they just disabled the broken core. To meet demand of these product lines perfectly good quad core CPUs got disabled and sold off as dual/triple editions. It was the luck of the draw if you got one of those and not a genuinely flawed chip.

Now, How much of that is true I don't know but that's what I remember reading at the time. A friend of mine did succesfully unlock his triple and ran for a long time.

[+] sireat|10 years ago|reply
The difference is that Intel is forcing this update (via Windows updates and by forcing mobo makers hands). Don't think AMD ever had that kind of power.

I am curious which AMD chips had the unlocking disabled?

I am still rocking AsRock 970 MB with AMD B50 which actually is an Athlon II X3 unlocked into a full blown Phenom II X4 (3 cores with no L3 cache into 4 cores with unlocked L3 cache).

[+] sireat|10 years ago|reply
This "software eating the hardware" is worrisome.

It used to be that at least you could depend on the hardware staying the same unless you chose to apply patches yourself.

Is it theoretically possible to change the microcode to actually add more features instead of disabling them?

Let's say Zen actually comes out better than expected and then Intel miraculously releases another update which re-enables OC ability?

[+] dbalan|10 years ago|reply
What are the ways in which this microcode update is enforced? Is it something that ships with your os? or something that user has to manually install like a BIOS update?
[+] s9ix|10 years ago|reply
Would probably be a BIOS update distributed from the motherboard manufacturer. As the article states, people could just not update,but finding hardware with the older BIOS will be more and more difficult over time.
[+] amluto|10 years ago|reply
What happens when this microcode patch is applied at runtime on an overclocked CPU?

Remember the Haswell mess when a microcode patch disabled TSX ? If you applied it after user code (glibc) detected TSX support, boom.

[+] rasz_pl|10 years ago|reply
you get a hang, happened with Win 10 on overclocked G3258. Win10 ships with mcupdate_GenuineIntel.dll containing microcode that ... disables Overclocking

Workaround is renaming/deleting mcupdate_GenuineIntel.dll and not updating BIOS ever again to avoid new microcode, all to keep cheapest 4.4GHz single thread cpu money can get.

[+] qb45|10 years ago|reply
> What happens when this microcode patch is applied at runtime on an overclocked CPU?

Paradox :)

Probably it'll reset conveniently so that you can restore default BIOS settings.

They can't let it run because that wouldn't change anything and I'm not sure if the microcode has a way to reliably switch some off-chip clock generator back to 100MHz.

[+] venomsnake|10 years ago|reply
Lets hope Mr. Keller did stellar job at AMD. Once again.
[+] rasz_pl|10 years ago|reply
Wouldnt count on that, best AMD marketing predictions promise 40% more IPC, that would still be 1-2 Intel generations behind. AMD marketing always overpromises, so we will end up with something between first-second i5 gen.
[+] AlexDanger|10 years ago|reply
So was it just one particular Asrock motherboard that allows this type of overclocking? Whilst my hardcore overclocking days are behind me, I have an i5-6500 and some kind of Asus mobo...I'm curious to take it for a test drive.
[+] onli|10 years ago|reply
To my knowledge all of the vendors supports that. You need a Z170 board and search a non-K bios for your model.
[+] Osiris|10 years ago|reply
One reason that I've always liked AMD is they have a limited number of products so they don't play games like this. AFAIK, every feature that an architecture supports is available on chips released. The only exception that I'm aware of is "black" edition allows for an unlocked multiplier, meaning you can overclock the CPU without overclocking the BUS.
[+] grawlinson|10 years ago|reply
They're basically disabling functionality in order to make a quick buck.
[+] glogla|10 years ago|reply
AMD Zen can't come soon enough.
[+] quickben|10 years ago|reply
Microcode giveth, microcode taketh away :)

It is interesting though how Intel waited so far (not even a statement?) , probably just to sell more CPUs overall.

[+] reflexing|10 years ago|reply
Good thing is we can load old microcode on Linux
[+] throwaway7767|10 years ago|reply
> Good thing is we can load old microcode on Linux

You cannot load old microcode anywhere. The CPU won't let you.

The OS feeds the CPU a blob, the CPU checks that it's signed by Intel (to prevent modifications), and it additionally checks that the version number is newer than the currently-running code. If it's not, it won't be loaded.

If you have a CPU with the old microcode versions, you can keep it around, but if you update your BIOS you'll find it will bring the new microcode in and you can't downgrade after boot. If you're lucky the BIOS manufacturer wasn't too careful with signing their BIOS and you can replace the microcode blob, but that's a huge hassle.

[+] raverbashing|10 years ago|reply
But then you don't get the Prime95 fix as well
[+] alexsoft|10 years ago|reply
AMD adopted same strategy, no overlooking for poor!
[+] dnlrn|10 years ago|reply
CPUs are complicated pieces of technology. During the manufacturing process, some parts have a better quality grade than others. The better quality parts allow some overclocking without producing errors and therefore they get put into the overclockable K-processors. The worse parts get put into non-overclockable processors and run fine using the default voltage.

Some of the non-overclockable cpus might work fine after overclocking, some might not. Intel definitely doesn't want the negative press when some kids decides to overclock their non-K CPU and break it during the process. So I understand the decision.

[+] userbinator|10 years ago|reply
Some of the non-overclockable cpus might work fine after overclocking, some might not. Intel definitely doesn't want the negative press when some kids decides to overclock their non-K CPU and break it during the process.

Have you participated much in the overclocking community? The whole point is that every CPU chip is different and can be overclocked by different amounts, some almost not at all. There is no "negative press", since anything past stock speed is a bonus which is what overclockers are trying to get. If CPUs were not working at stock speeds, that would be a reason for "negative press".

[+] oliwarner|10 years ago|reply
Sorry, the negative press argument is utter nonsense.

If you run any hardware outside specifications, you expect it to fail. People brick phones and ruin engines but there isn't a backlash against people trying to jailbreak their phone or modify their cars. If anything, the people that matter —the enthusiast market for these devices— are demanding that their devices be more customisable. The press and other consumers don't give two hoots about little Jimmy trying to rice 5GHz out of his $100 CPU and turning it into liquid magma. Stupid kid was stupid.

The opposite is true though. If lil Jim manages to get a $5000 part for $100, other consumers are going to factor that into their purchasing decisions.

What is most concerning is that this is a part that has been out and about for a little while. There are dozens of guides recommending certain CPUs for this that Intel are going to patch up now. The articles and their recommendations will remain out there though. It's false advertising by the back door.

[+] onli|10 years ago|reply
And that's just not true.

There would be no negative press for intel. Everyone with the shlightest knowledge about overclocking knows that overclocking can damage your parts. And like stated, parts breaking without voltage increase is highly unlikely. But still: Assume I buy an Intel Non-K processor, base-overclock it and it breaks. How on earth would I be able to produce negative press for Intel by publishing that?

It's simply a profit optimization. K-processors cost more, people who want to overclock had the option to buy non-K, that reduced sale numbers of the K line. Also the i7-6700 is clocked way below the i7-6700K, it was a nice option to get the cheaper version and up it to K level, saving 100€ for some time (prices changed).

Behavior like that is why I buy AMD.

[+] daniel-cussen|10 years ago|reply
Overclocking isn't just a joy ride. It gives you more for your money, reducing the demand for the more premium version.
[+] nbzklr|10 years ago|reply
I've never heard of a CPU "breaking" during non-LN2 Level OC.