I own a desktop with the MSI P965 NEO-F motherboard installed. As you can see from the link, this motherboard can only accept Intel Core 2 Duo - generation processors, with the LGA775 socket. It is a decade-old motherboard.
I currently have the Intel® Core™2 Duo E6600 installed (I don't have enough reputation to post many links, kindly Google it for specifications). It came with its original cooling unit, which I have not touched since. I am considering upgrading the CPU to the best possible CPU that my mobo can support, the Intel® Core™2 Quad Q9550. To that end, my question is simple: would I need to also change the cooling unit, or is it sufficient that I just purchase the processor itself? Not needing to purchase the cooling unit would reduce my costs significantly.
I should also note that I have looked up this relevant thread, yet no mentioning of the cooling unit is made. I am also pretty confident that despite the increased TDP of the quad core, I will have no issues pertaining to power supply, since I am currently able to supply about 350 Watts more than my maximum power usage.