I currently have an Intel Core i5-4460S CPU @ 290GHz, 4 Cores, 4 Logical Processors. I have an Lenovo Desktop. 300S-08IHH Desktop (ideacentre) - Type 90F1
What you have to do is ask the motherboard manufacturer what processors are compatible with their motherboard bios. Then, you can select from those processors.
It is not enough for the new processor to be socket compatible. It must also be chipset and bios compatible.
Do not believe "some" website. Only the manufacturer site knows for sure.
Is this a home built system or a store bought system?
If home built, look on the motherboard. There will be some manufacturer name (like asus, msi, asrock, etc) and a model number.
If store bought, there will be a lable on the back or bottom of the case that tells you the manufacturer and model (of the system).
Armed with that information, contact the manufacturer.