I'm curious about how data buses work in modern CPUs, especially those where the Northbridge functions are integrated into the CPU itself. I know that the front-side bus (FSB) used to connect the processor to the motherboard's chipset, but with many logical components like the memory controller now on-die, I'm wondering how the internal hardware interfaces with these changes. Does the architecture of the FSB differ from technologies like QPI or HyperTransport? Additionally, where can I find more information about how processors communicate with system components through these data transmission buses?
2 Answers
These days, most CPUs don't use a traditional FSB or Northbridge anymore. The memory controller is integrated right into the CPU and uses some kind of internal bus design—details about which aren't usually disclosed. So, we really don't have a clear picture of how it operates under the hood.
In modern architectures, there's no distinct FSB or Northbridge as we knew it. Since everything's integrated onto the chip, the internal configurations can vary widely and don't need to stick to older standards. If you're interested, check out some resources about AMD's Infinity Fabric or similar technologies; there's some great info out there!
Thanks for the tip! So you're saying the classic idea of a 'system bus' is pretty much obsolete now? It makes sense for everything to be encompassed within the CPU itself.