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Performance Impact of Spectre and Meltdown Mitigations on Windows Systems

cloudblogs.microsoft.com

11–20 of 39 posts

Re: Performance Impact of Spectre and Meltdown Mitigations on Windows Systems

#11
post #2

"We currently support 45 editions of Windows. Patches for 41 of them are available now through Windows Update." Wow. I have to admit, that number larger than I would have guessed. (I probably would have said 20.) But ultimately not too surprising.

Did they not cause this themselves when making 'home' 'professional' 'enterprise' and so on versions of each of their major versions?

Re: Performance Impact of Spectre and Meltdown Mitigations on Windows Systems

#12
post #6

I would really like to know exactly what compiler changes they made to mitigate Spectre.

It’s probably the retpoline replacement for indirect branches, which traps the speculative execution of the untaken branch in a loop

Re: Performance Impact of Spectre and Meltdown Mitigations on Windows Systems

#13
post #4

tldr: should I never ever update my Windows 8 again lest it becomes slow af?

It seems so. Sooner or later people will post some benchmarks so we'll have more precise knowledge. At this point the statements from MS are a bit fuzzy.

Microsoft will do so as well:

>We will publish data on benchmark performance in the weeks ahead.

Re: Performance Impact of Spectre and Meltdown Mitigations on Windows Systems

#14
It's completely anecdotal, but I'm convinced my Phenom-II x6 system's IO has slowed to a crawl in the last few days...

edit: Oh, though it seems there's another thread discussing how the mitigations have slowed down "Haswell and older CPUs significantly".

edit edit: like an idiot, i didn't include the link: https://news.ycombinator.com/item?id=16113289

Re: Performance Impact of Spectre and Meltdown Mitigations on Windows Systems

#15
post #9

Earlier quoted context omitted.

It seems so. Sooner or later people will post some benchmarks so we'll have more precise knowledge. At this point the statements from MS are a bit fuzzy.

Fuzzy, yes. But they do declare that a lot of people will notice slow downs day to day.

They need to ve very conservative in the statements and err on the side of caution. It's better for people to find out is not as bad as they thought than to find out it's worse than they thought.

Re: Performance Impact of Spectre and Meltdown Mitigations on Windows Systems

#17
post #2

"We currently support 45 editions of Windows. Patches for 41 of them are available now through Windows Update." Wow. I have to admit, that number larger than I would have guessed. (I probably would have said 20.) But ultimately not too surprising.

Dealing with such a large number of versions must be a nightmare. A nightmare of Microsoft's own creation...

Re: Performance Impact of Spectre and Meltdown Mitigations on Windows Systems

#18

Anyone know if there are performance impacts from the macOS updates released recently to address Spectre/Meltdown?

Seems like syscalls are a lot more expensive, which may or not affect your daily work.

https://reverse.put.as/2018/01/07/measuring-osx-meltdown-pat...

Re: Performance Impact of Spectre and Meltdown Mitigations on Windows Systems

#19
Random conspiracy theory:

This whole episode of CPU bugs and fixes that cause performance problems (most notably on older hardware) is exactly what the tech industry needed to stimulate consumers into refreshing their old hardware that was previously running fine.

It's almost like planned obsolescence. Msybe it was orchestrated.

(I don't think this actually likely, but it's interesting that it could be rather beneficial in the end for some)

Re: Performance Impact of Spectre and Meltdown Mitigations on Windows Systems

#20
post #2

"We currently support 45 editions of Windows. Patches for 41 of them are available now through Windows Update." Wow. I have to admit, that number larger than I would have guessed. (I probably would have said 20.) But ultimately not too surprising.

Dealing with such a large number of versions must be a nightmare. A nightmare of Microsoft's own creation...

This is why I tacitly approve of forced (or pressured) automatic updates for Windows, macOS, and iOS. Everyone is probably safer when most efforts to fix Zero day exploits, General hardening, etc. are concentrated on fewer versions.

When I want freedom to do what I want with my computer, I run Linux, but for my Apple devices I want auto updates.

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