I am new to the computer technology and would like to know exactly this: the i-7 720 processor from Intel is a quad core but it is only rated 1.6 with a turbo of 2.8. Are these numbers per core or all together?
It is all together. 1.6Ghz is what the chip normally runs at, but if necessary it can step it up to 2.8Ghz in turbo mode. For most users, this is plenty, as just like you said, it is a quad core and it has hyperthreading, which means it has for virtual cores. In other words, it can handle just about anything in a pretty snappy fashion.