I'm not really sure what exactly they are. I know I've had to update my BIOS to be able to use newer versions of CPUs that still fit in the old sockets before [1]. I know I've seen Windows updates for both the motherboard's chipset and for the CPU. But what difference any of that has made, I don't know.
[1] Actually, that particular instance was a complete pain in the ass, because I had bought all of the parts new, but the motherboard didn't have the latest BIOS on it, and I didn't have a compatible CPU on hand. This was also before the liberal return policies that online vendors now have, so I ended up just ordering a different motherboard completely.
[1] Actually, that particular instance was a complete pain in the ass, because I had bought all of the parts new, but the motherboard didn't have the latest BIOS on it, and I didn't have a compatible CPU on hand. This was also before the liberal return policies that online vendors now have, so I ended up just ordering a different motherboard completely.