Should I build a new PC?

[Kin Hell]

I wouldn't advise AMD to anyone, but RE Intel i3, i5 & i7 series, there are older versions of all of them.

In terms of performance, i7 is the best of the series with more cores & bigger cache's, whereas i3 the lowest of the series. But then in each series, you get different chip speeds also effecting their respective performance.

Also, with every generation of Intel CPU being released, there is usually a Chip-set change as well, sometimes with more or less Pin contacts in the CPU socket. Now you know this, just don't think you can put any generation of i7 CPU on any i7 capable board. The socket has to be the right one.