Install a sandy bridge cpu in Intel DB75EN

[ThinkPad560X]

As of right now my upgraded IBM tower has a Intel DB75EN board with 1 8GB RAM stick and a Intel Celeron 1155LGA Processor and a EVGA Nvidia GT 520 card. I am eventually going to get a Intel Core i7 for the board with 3 more 8GB sticks "Max at 32GB" and a EVGA Nvidia GTX 980Ti.

The box that the board came in said supports 2nd and 3rd generation 1155LGA processors. What is the difference of the 3rd gen and the 7th gen if it still is a 1155LGA socket?

[axur-delmeria]

LGA 1155 only supported two generations of processors:
Sandy Bridge (2nd-gen Core i series)
Ivy Bridge (3rd-gen Core i series)

Either the wording on the DB75EN's box is ambiguous, or you misread it.

Between Sandy and Ivy, the biggest difference is the integrated graphics, where Ivy has a significant lead. OTOH that's irrelevant in your case since you have a video card.
The difference in CPU performance isn't much, only 3-6% at the same clock speed.



Just for reference, here are the common sockets for the Core i series:

LGA 1366 --> 1st gen Core i7 9xx (triple-channel memory)

LGA 1156 --> 1st gen Core i3, i5, i7 (dual channel memory)

LGA 1155 --> 2nd and 3rd gen Core i series "Sandy Bridge" and "Ivy Bridge"

LGA 1150 --> 4th and 5th gen Core i series "Haswell" and "Broadwell"

LGA 1151 --> 6th gen Core i series "Skylake"

[ThinkPad560X]

They don't make a 1155 Skylake? Awhile back Intel also announced they are discontinuing Intel motherboards "Their own made brand motherboard witch I have one of"

[axur-delmeria]

They don't make a 1155 Skylake?

Nope. That's how Intel does things: new feature, new socket-- in this case DDR4.

CPU sockets rarely last more than 2 generations.

Awhile back Intel also announced they are discontinuing Intel motherboards

Low profits, maybe? They probably weren't popular since they were locked down (not many configurable options in BIOS).