all FX series. this doesnt make a huge difference, altough 512kb is ideal, 1mb is a nice plus.core technology: two choices, 90nm or 130nm. 90nm run cooler and overclock higher. 130nm are older technlogoy. all new AMD chips are 90nm.single or dual core: obviously, dual is better, but it all depends what you do. most games and software is very linear, so only one core is used, while other sits idle