> What about Pentium II and 3? I'm using 5 such machines (and also a Pentium > MMX). I've tried a spectre test before and it wasn't reading anything useful. > Don't know about meltdown. Is there a complete test program? (The web is so > full of crap that even google can't find anything useful.)
Pentium MMX does not speculate. Pentium II does. For meltdown there are some reasonably easy tests to run to look for a positive. Proving a negative is much much harder however and as far as I am aware nobody has done a full evaluation of processors that old. For x86 speculation came in (as far as I can tell) in AMD Am5x86 Cyrix 5x86, but branch predictors are disabled by default according to the docs Cyrix 6x86, branch prediction on by default Pentium Pro There are later processors that don't have speculation: Quark series, Nat Semi/Cyrix Geode, earliest AMD geode (I think), some Intel Atom processors. The more obscure ones - the Transmeta apparently may, the IDT Winchip documentation strongly implies it doesn't, the Vortex86 (aka SiS55X/Rise mP6) says it doesn't and things like the NexGen I have no idea about. The problem is that it's very hard to definitively answer questions on these processors and vulnerabilities like they are obsolete, almost nobody uses them for anything but retro stuff and the return on the effort of figuring out defiitive answers is close to nil. Alan
