While LGA1156 will probably soon be superseded, the other three are likely to be with us for some time.
LGA775 will probably be relegated to budget machines and eventually phased out.
It’s affordable, you can do it on almost any machine (including many laptops), and it doesn’t require much tech know-how.
If you're dealing with a current-generation system, you have two possibilities: LGA1155 and LGA1366.
This means that if you're contemplating a significant, generational upgrade for an Intel CPU, it will probably also involve replacing your motherboard.
In Linux, I know there are ways of doing this from the operating system itself, instead of having to go through the BIOS, like this and this. I believe you can achieve lower frequencies from power options menu: image link Setting maximum and minimum processor state to some percentage will probably fix the frequency on some level depending on your maximum CPU frequency.
Identification Buying a New Motherboard Replacing the Processor (Desktop Units)Socket 479 and other mobile sockets Replacing the Motherboard Reassembling the Computer Community Q&A As computer technology advances, new software will demand more from your computer, giving you the impression that it is getting slower, taking more time to process events. Upgrading your CPU (Central Processing Unit) is one of the most beneficial things you can do to make your computer run lag-free.
If you plump for an Intel processor, the matter is complicated by the plethora of socket formats involved.