No. DynamicPGO was first introduced in .NET 6 but was not mature and needed two releases worth of work to become enabled by default. It needs no user input and is similar to what OpenJDK Hotspot has been doing for some time and then a little more. It also is required for major features that were strictly not available previously: guarded devirtualization of virtual and interface calls and delegate inlining.
Also, IIS hosting through Http.sys is still an option that sees separate set of improvements, but that's not relevant in most situations given the move to .NET 8 from Framework usually also involves replacing Windows Server host with a Linux container (though it works perfectly fine on Windows as well).
On Regex, compiled and now source generated automata has seen a lot of work in all recent releases, it is night and day to what it was before - just read the articles. Previously linear scans against heavy internal data structures (matching by hashset) and heavy transient allocations got replaced with bloom-filter style SIMD search and other state of the art text search algorithms[0], on a completely opposite end of a performance spectrum.
So when you have compiler improvements multiplied by changes to CoreLib internals multiplied by changes to frameworks built on top - it's achievable with relative ease. .NET Framework, while performing adequately, was still that slow compared to what we got today.
Sure. But static PGO was introduced in .Net Framework 4.7.0. And we're talking about apps in production, so there's no excuse NOT to use static PGO on the .net framework 4.7.0 version.
And you have misrepresented the contents of the blogs. The projects discussed in the blogs are typically claiming ~30% improvements (perhaps because they weren't using static PGO in their 4.7.0 incarnation), with two dramatic outliers that seem to be related to migrating from IIS to Kestrel.
It’s a moot point. Almost no one used static PGO and its feature set was way more limited - it did not have devirtualization which provides the biggest wins. Though you are welcome to disagree it won’t change the reality of the impact .NET 8 release had on real world code.
It’s also convenient to ignore the rest of the content at the links but it seems you’re more interested in proving your argument so the data I provided doesn’t matter.
Also, IIS hosting through Http.sys is still an option that sees separate set of improvements, but that's not relevant in most situations given the move to .NET 8 from Framework usually also involves replacing Windows Server host with a Linux container (though it works perfectly fine on Windows as well).
On Regex, compiled and now source generated automata has seen a lot of work in all recent releases, it is night and day to what it was before - just read the articles. Previously linear scans against heavy internal data structures (matching by hashset) and heavy transient allocations got replaced with bloom-filter style SIMD search and other state of the art text search algorithms[0], on a completely opposite end of a performance spectrum.
So when you have compiler improvements multiplied by changes to CoreLib internals multiplied by changes to frameworks built on top - it's achievable with relative ease. .NET Framework, while performing adequately, was still that slow compared to what we got today.
[0] https://github.com/dotnet/runtime/tree/main/src/libraries/Sy...