A Microsoft official confirmed today that some devices running on older Windows versions will see a significant slowdown and decrease in system performance after applying the Meltdown and Spectre security patches.
More precisely, this is how Meltdown and Spectre patches are going to affect Microsoft's products, as detailed today by Terry Myerson, Executive Vice President of the Windows and Devices Group.
"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," Myerson said.
"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," the Microsoft exec added.
The slowdowns were to be expected due to the nature of the bugs and the type of patching required to get them fixed. Many described the Meltdown and Spectre vulnerabilities as flaws in the basic design of modern processors, so the patches were expected to cause problems.
This patch literally invents new computer science to work around the side-channel CPU issues. Continuing to be in awe and massive kudos to all the OS vendors who had to probably re-do entire feature roadmaps to handle this work. tl;dr Tokens/Processes now have "Security Domains". pic.twitter.com/DjddA97GZ7— Alex Ionescu (@aionescu) January 4, 2018
Intel said its processors would be affected based on the type of operations the CPU would carry out, saying that syscall-heavy processes would suffer the most.
We knew Windows systems would be affected when a data scientist reported last week that Python now takes more to process the same data on a patched Windows 7 PC.
Some of the Meltdown and Spectre mitigations introduced in the Linux kernel caused similar performance dips to the ones now disclosed by Microsoft.
Initial estimations said the Linux Meltdown and Spectre patches would produce between 5% and 50% slowdowns, but further tests and benchmarks proved many claims exaggerated. RedHat cut down the performance penalties on its systems to a range from 1% to 20%.
Many companies should expect their AWS cloud computing bill to go up because it now takes more time to process the same amount of data.
Now who will end up paying for this? In our shop, this translates into seven figures in our AWS bill. https://t.co/GlSFqok8PX— andreasdotorg (@andreasdotorg) January 6, 2018