AM3 can take an AM3+ CPU and AM3+ can take any AM3 CPU, therefore incorrect. As for 28nm, I have never seen it as that much of an manufacturing process upgrade. GDDR5 will likely only be for BGA, which kind of defeats the upgrading purpose.
[/quotemsg]
Uhh...NO! AM3+ CPUs have an extra pin that would break off if you tried to put them into an AM3 board.
Wikipedia agrees with me too:
http://en.wikipedia.org/wiki/Socket_AM3
AM3 is 941 pins, AM3+ is 942 pins.
That would get someone a broken CPU if they tried to put an AM3+ CPU into an AM3 board. Please do not instruct someone to do that. It would make a new CPU into a really expensive paper weight, and they likely couldn't get it RMA'ed because the issue was user error, not a manufacturer defect.
EDIT: Doing some more research...some boards were AM3 with an AM3+ socket installed for forward compatability, but this is not recommended, as trying it on a board that did not have a compatible socket would be seriously bad. (Bent pins, bad power regulation etc.)[/quotemsg]
No, via BIOS update, the AM3 boards (890 series which could handle 130W+ TDP) could be used on Bulldozer or Piledriver CPUs, I believe the AM3+ CPUs only have 938 or 939 pins in them, those compatible mobos never had an AM3b socket. If I stuck a 8350 even in an old 790 board, it would come out with no bent pins, but would not boot of course.
[/quotemsg]
Well, supposing that's the case, AMD does not support it, and it will void any support from the MB manufacturer, so I still would advise against it...even if it hypothetically works under certain circumstances.
EDIT: The socket is wider on the AM3+ boards...you're sure they all fit? I don't know...I still wouldn't recommend it either way. It was never designed to for the newer architectures.[/quotemsg]
AM3+ CPUs have the same pin width, length and count. AM3 CPUs will fit in AM3+ Boards without a problem, the width is just to prevent bent pins and the chip will still work fine.