I had both Intel and AMD computers in that era. Afaik, AMD K7 Athlon had more MHz/GHz, run on less power (Watt) and were cheaper at that time than the Intel Pentium 4. But performance wise both were almost equal and the Pentium 4 3GHz model introduced the HT (HyperThreading) technology (multithreading performance). Athlon 64 on the other hand were the first x86-64 CPUs.
The AMD special sauce back in those days was not raw clock speed, but IPC. AMD would market an Athlon 2400 e.g., clocked significantly below 2.4GHz, but roughly comparable in terms of performance to a 2.4GHz Pentium.
This, combined with a lower price point, is what made AMD chips so desirable. I do not recall power consumption.
It's interesting that in the course of <10 years, the positions flip-flopped, and Intel's architecture dominated AMD in IPC and power consumption, making price AMD's primary weapon in the CPU battles. There is also a small draw from AMD's construction equipment being much more clock-happy than Intel's current offerings, so some enthusiasts only concerned with clock speed still preferred AMD in recent times.
The primary benefit is that you can put together an entire system based on one of AMD's top offerings right now for less than Intel's best CPUs cost. AMD is strictly a budget option currently.
