Intel CPU bug will cause slowdown for all programs once patched.

Intel CPU bug will cause slowdown for all programs once patched.

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nanoflower

/https://www.theregister.co.uk/2018/01/02/intel_cpu_design_flaw/

A fundamental design flaw in Intel's processor chips has forced a significant redesign of the Linux and Windows kernels to defang the chip-level security bug.

Programmers are scrambling to overhaul the open-source Linux kernel's virtual memory system. Meanwhile, Microsoft is expected to publicly introduce the necessary changes to its Windows operating system in an upcoming Patch Tuesday: these changes were seeded to beta testers running fast-ring Windows Insider builds in November and December.

Crucially, these updates to both Linux and Windows will incur a performance hit on Intel products. The effects are still being benchmarked, however we're looking at a ballpark figure of five to 30 per cent slow down, depending on the task and the processor model. More recent Intel chips have features – such as PCID – to reduce the performance hit.

Replies 9

nanoflower

Well this is good news from the phronix web site. Looks like the initial report from the Register may have overstated the impact of the bug. Still, having a bug like this that impacts CPUs from as far back as 10 years ago isn't a good thing.

 

https://www.phoronix.com/scan.php?page=news_item&px=x86-PTI-Initial-Gaming-Tests

With the recently published Initial Benchmarks Of The Performance Impact Resulting From Linux's x86 Security Changes, one of the common questions that came up is whether gaming performance is adversely affected by the x86 Page Table Isolation changes recently merged to the Linux kernel.

Linux gaming performance in initial testing doesn't appear to be affected. Then again, we personally didn't expect it to be much considering it's more isolated than some of the other syscall / context switching heavy workloads benchmarked. But for those concerned whether running the patched Linux kernel could lead to a drop in frame-rates, it doesn't appear to be when firing up some of the common Linux games on Steam.


zakware47

thank you bro

thank you

Legrun

nanoflower said:

Well this is good news from the phronix web site. Looks like the initial report from the Register may have overstated the impact of the bug. Still, having a bug like this that impacts CPUs from as far back as 10 years ago isn't a good thing.

 

https://www.phoronix.com/scan.php?page=news_item&px=x86-PTI-Initial-Gaming-Tests

With the recently published Initial Benchmarks Of The Performance Impact Resulting From Linux's x86 Security Changes, one of the common questions that came up is whether gaming performance is adversely affected by the x86 Page Table Isolation changes recently merged to the Linux kernel.

Linux gaming performance in initial testing doesn't appear to be affected. Then again, we personally didn't expect it to be much considering it's more isolated than some of the other syscall / context switching heavy workloads benchmarked. But for those concerned whether running the patched Linux kernel could lead to a drop in frame-rates, it doesn't appear to be when firing up some of the common Linux games on Steam.

Has anyone heard anything from DELL or Alienware on how this might impact our gaming systems?

Drink deep, or taste not the Pierian spring.

wilbymilstone

Glad I'm an AMD user!

It's the terror of knowing what this world is about! Watching some good friends screaming "Let me out"!

paprika911

Out of brand patch out soon on Windows if you are running Windows 10. Updating your machine is a good idea, so check your Windows update soon.

According to the report, the update is a “rare out of brand” security update and will be issued for all supported versions of Windows. The security update is set to automatically roll out to all Windows 10 desktops today at 5 PM ET, though we’re not seeing it on any of our systems just yet. It’s also set to become available on other Windows 7 and Windows 8 systems, though it will not appear automatically on these systems until Tuesday, January 16.

Source: https://www.onmsft.com/news/microsoft-to-release-emergency-windows-update-to-address-intel-amd-processors-security-concerns 


nanoflower

wilbymilstone said:

Glad I'm an AMD user!

 

That isn't going to keep you safe. Turns out that only one issue seems to be tied to Intel. There are many others and they impact practically every CPU made in the past 10 years or so.

https://spectreattack.com/#faq-fix

"Which systems are affected by Meltdown?

Desktop, Laptop, and Cloud computers may be affected by Meltdown. More technically, every Intel processor which implements out-of-order execution is potentially affected, which is effectively every processor since 1995 (except Intel Itanium and Intel Atom before 2013). We successfully tested Meltdown on Intel processor generations released as early as 2011. Currently, we have only verified Meltdown on Intel processors. At the moment, it is unclear whether ARM and AMD processors are also affected by Meltdown.

Which systems are affected by Spectre?

Almost every system is affected by Spectre: Desktops, Laptops, Cloud Servers, as well as Smartphones. More specifically, all modern processors capable of keeping many instructions in flight are potentially vulnerable. In particular, we have verified Spectre on Intel, AMD, and ARM processors."

"Meltdown breaks the most fundamental isolation between user applications and the operating system. This attack allows a program to access the memory, and thus also the secrets, of other programs and the operating system.

If your computer has a vulnerable processor and runs an unpatched operating system, it is not safe to work with sensitive information without the chance of leaking the information. This applies both to personal computers as well as cloud infrastructure."

 

"Spectre breaks the isolation between different applications. It allows an attacker to trick error-free programs, which follow best practices, into leaking their secrets. In fact, the safety checks of said best practices actually increase the attack surface and may make applications more susceptible to Spectre

Spectre is harder to exploit than Meltdown, but it is also harder to mitigate. "


nanoflower

Legrun said:

Has anyone heard anything from DELL or Alienware on how this might impact our gaming systems?

 

I doubt they know what impact if any it will have. It looks like it may be some time before the full impact of Meltdown and Spectre (the two names being used for the issues) are understood and fixes in place. Until that happens from the various OS vendors it's not possible for anyone at Dell/Alienware to know what the full impact will be. Clearly there may be some performance impact for all systems (not just Dell/Alienware.)


hirschy19

Never liked out of order executions, I think executions need order. I like to get there first, stand in front row closest to the guillotine; and look into the bucket.


sharkyali

thaaanks!