PCIe doesn't have to do anything as complex as a general-purpose CPU. Increasing the frequency is a lot easier when you don't need to worry about things like heat, pipelining, caching, branch prediction, multithreading, etc. It's just encoding data and sending it back and forth. We've gotten very, very good at that.
It wasn't really like it was impossible before now - it's just more that it wasn't in demand. With the proliferation of SSDs transferring data over PCIe, it's become much more important - so the extra cost of better signaling hardware is worth it.
Not to dismiss it completely, it's still a hard problem. But it's far easier than doubling the frequency of a CPU.
It wasn't really like it was impossible before now - it's just more that it wasn't in demand. With the proliferation of SSDs transferring data over PCIe, it's become much more important - so the extra cost of better signaling hardware is worth it.
Not to dismiss it completely, it's still a hard problem. But it's far easier than doubling the frequency of a CPU.