Knoppix 9.1
Been playing with some old computers to see if they still work with current linux. First a thin client with AMD G-T52R and 4GB RAM. This is a single core processor with "one thread". Meaning its a single core that can boot a 64bit system. It however is only 1.5Ghz... It booted 32bit version Knoppix off SSD installation, no problem. Even acceptably usable. I launched Kindle for PC in WINE 7.1. It worked until I tried using the dictionary function, WINE CRASHED leaving me back to desktop, Knoppix didnt crash and I could reopen Kindle on WINE if I wanted. Marginal but acceptable. Put it this way, you really dont want to try and watch streaming video in browser, dropped frames like nothing else. The only 64bit I got to boot was LXDE spin of Fedora 35 installed to a SSD. It booted...slowly. But once I opened Firefox, it crashed. I couldnt boot Fossapup.
Now another with similar processor is old HP DC5000 or might be DC5700, cant remember now. Anyway it has a hyperthreaded single core P4 processor, something like 2.8Ghz. Twice as fast as the single core AMD. It came with 32bit XP back in the day, 64bit was just marketing thing, really wasnt much 64bit anything out there at the time. Fine until one year my tax software sniffed for XP and rejected running on it. I think it could otherwise have continued to run, its TAX SOFTWARE, not something that does much other than ask questions and do calculations in background. No serious graphics involved. But anyway installed unactivated version win10 (64bit) and locked it down so no background processes running and no phoning home for updates. Takes forever to boot but runs ok once booted. Well of course the Knoppix being 32bit booted quickly and ran well. Nothing else would boot from SSD, so tried live dvds from usb dvdrom. Ok, Slacko 64bit was fastest (I didnt have any SSD installed version to try). Fossapup 9.5 64bit which wouldnt boot from SSD would finally boot as live dvd, but it wasnt happy about it and took longer than anything else. Fat Dog aborted during boot! Yea got a message popped up, aborted! Interestingly MX21 (64bit) though slow booting, was similar to win10 in time to boot, and once booted did fine. Fedora 35 and Manjaro and Debian 11 took extra long to boot from dvd, but finally did and were ok once booted.
Now moving up to super slow AMD E-350 dual core. Sure somewhere there might be even slower dual core processor, maybe some old ATOM, but it wouldnt be easy to find one. Didnt try the dvds. MX19 wouldnt boot. Neither would Fossapup. Interestingly LXDE spin of Fedora 64bit did best on it. Knoppix had no advantage here, though it also booted fine. Its weird but I think I almost prefered Knoppix on the AMD G-T52R over the E-350. I expect Slacko 7 might do well.
Anyway, my point, you really have to try different distributions especially on older hardware to find one that works best. Knoppix however impressed me by booting relatively fast from everything I tried it on and running pretty well. Its one you no longer hear much about. Initiation sequence starting......