Yeah there's not really a hard line between "improved version of old architecture" and "new architecture". Zen 2 seems to be about as big a change from Zen+ as

Yeah there's not really a hard line between "improved version of old architecture" and "new architecture". Zen 2 seems to be about as big a change from Zen+ as Haswell was from Ivy Bridge. Ultimately what matters is how much they improved from the old versions. Supposedly Ice Lake is going to have 18% higher IPC than Skylake which seems like it will involve some pretty radical changes. Will certainly be interesting to see how that and Zen 3 turn out.