It’s vulnerable to Spectre even to Variant 2 but they define it as a very low risk what ever that means and only issuing fixes for Variant 1.
It looks like the second variant of Spectre the out of bounds check is the culprit here; if AMD isn’t vulnerable at all it would be great but to me it looks like they are sitting on the fence to wait and see where the exploits go.
>Older versions of Windows have a larger performance impact because Windows 7 and Windows 8 have more user-kernel transitions because of legacy design decisions, such as all font rendering taking place in the kernel.
They're claiming the opposite:
>> With Windows 10 [...] we expect that some users will notice a decrease in system performance.
>> With Windows 8 and Windows 7 [...] we expect most users to notice a decrease in system performance.
>> Older versions of Windows have a larger performance impact because Windows 7 and Windows 8 have more user-kernel transitions because of legacy design decisions, such as all font rendering taking place in the kernel.
How can Intel possibly continue to claim this when the majority of home and business PC users are on Windows, and probably mostly on hardware older than Skylake too?
For most home/office tasks (web browsing, email, office documents) most of the time is spent waiting for user input or network responses. Even on a really slow old Atom-based netbook I suspect that the difference will be at worst "noticeable" and not significant for these tasks (i.e. it isn't going to make any difference while the app is waiting for your next key-press).
Older games that make many small calls to the graphics hardware will be affected but unless you are running them on really old hardware you'll not notice that either as they won't tax newer hardware even with the extra work. Newer games will be using more efficient techniques anyway.
Startup times are likely to be affected, both OS and individual application, but that is generally a once-per-session matter, and of course there will be some applications (or some workflows using applications otherwise relatively unaffected) that will see a difference, but not the majority.
Older OSs may be more starkly affected because of design changes since. For instance until 10 Windows performed font parsing and rendering in the kernel so text heavy applications might see some extra display lag after these patches. Low-memory situations might be more affected too, as RAM starvation increases the amount of IO happening during normal operation.
Developers are far more likely to notice, I've seen some bad before/after benchmarks for build processes. Long-running tasks, particularly those performing IO such as video encoding, are more likely to make the differences visible too (10% extra on a many-hour encoding task could add up to something pretty inconvenient). It is expected that certain server loads are going to be the worst hit. But none of this paragraph's "things that will be affected" are typical home/business use cases for the majority.
They're estimating 6% slowdown based on SYSmark 2014. I quickly skimmed the whitepaper and think this is probably reasonable; there's a mix of CPU-bound and I/O-bound tasks, and the CPU-bound tasks won't be impacted. Most home users are still on spinning disks, so that's your bottleneck for I/O, not the additional syscall overhead.
A 6% slowdown is imperceptible to a human. For tasks that don't need a lot of CPU power (like office applications and web browsing) even a 30% slowdown is not that big a deal.
Microsoft claims CPUs post 2015 only have unnoticable slowdown.
it could do with a pcie sdd and maybe a gpu upgrade but it's still perfectly serviceable. the only thing that has failed is the motherboard (was able to replace that for 110 AUD) and the CPU fan (i bought the wrong one and burned the bearings out because it was for lower TDP cpus).
All I really know is that it won't be faster--thanks.
> Windows 10 PCs with Haswell or older processors will see "more significant slowdowns" and Microsoft notes that a segment of customers may "notice a decrease in system performance”.
> Windows 7 and Windows 8 PCs powered by Haswell or older processors will see a "decrease in system performance" for "most users".
Does it mean that if you care about performance, it's better to use Windows 7 instead of 10? It's not spelled out explicitly, but they way they worded it suggests so.
> For context, on newer CPUs such as on Skylake and beyond, Intel has refined the instructions used to disable branch speculation to be more specific to indirect branches, reducing the overall performance penalty of the Spectre mitigation. Older versions of Windows have a larger performance impact because Windows 7 and Windows 8 have more user-kernel transitions because of legacy design decisions, such as all font rendering taking place in the kernel. We will publish data on benchmark performance in the weeks ahead.
An article in the verge states "Windows 7 and Windows 8 will be the worst hit simply because these older operating systems have features like kernel-level font rendering that will be impacted by the Spectre and Meltdown mitigations even further than Windows 10."
> Older versions of Windows have a larger performance impact because Windows 7 and Windows 8 have more user-kernel transitions because of legacy design decisions, such as all font rendering taking place in the kernel. We will publish data on benchmark performance in the weeks ahead.
In other words: If the fix would cause Windows 7 to lose X% performance, Windows 10 would lose that same X% plus any Y% advantage it had over Windows 7.
(This is just a guess, of course.)