>A CPU for games would have very fast cores, larger cache, faster (less latency) branch prediction,
The CPU industry stayed on this path for as long as it were physically possible, even long after the time when it hit diminishing returns on single thread performance divided by (area*power). Pentium 4 was the last CPU of this single-core era.
If you look closely at the microarchitecture of the modern desktop CPU, the out-of-order execution, caches and branch prediction are already maximized (to the point that >2/3ds of die area is cache). Multi-core has become mainstream only after all other paths became exhausted.
The reason Moore's law failed to keep pace is as you start to pack the transitors close enough you get a lot more heat and current leakage, the amount of work spent doing error correction increases quickly and becomes prohibitive.
The CPU industry stayed on this path for as long as it were physically possible, even long after the time when it hit diminishing returns on single thread performance divided by (area*power). Pentium 4 was the last CPU of this single-core era.
If you look closely at the microarchitecture of the modern desktop CPU, the out-of-order execution, caches and branch prediction are already maximized (to the point that >2/3ds of die area is cache). Multi-core has become mainstream only after all other paths became exhausted.