“Clear Linux has led Linux x86_64 performance not only on Intel desktop/mobile/server hardware but on AMD systems too.”
Intel killed Clear Linux after a decade of making every other distro look slow. On dual Xeon Max 9468 processors it ran roughly 48% faster than Ubuntu out of the box. Part of that gap is Ubuntu defaulting to the schedutil CPU governor instead of performance, which is a questionable choice for server workloads. But the optimization work in Clear Linux went far deeper than governor settings. Intel spent years proving that Linux distributions leave massive performance on the table, then shut down the project that proved it. The assets are abandoned and unmaintained now.