PC processors entered the Gigahertz era today in the year 2000 with AMD's Athlon

Thermal and Frequency Limits

• Several comments explain why ~5–6 GHz seems like a wall: dynamic power scales with capacitance × voltage² × frequency, so higher clocks explode power and heat.
• Overclocking records near 9 GHz use liquid nitrogen/helium and hundreds of watts per core, seen as irrelevant to reliable consumer chips.
• Some argue 10 GHz CPUs “will never be done in silicon”; others think it would require exotic cooling, new semiconductors, optics, or reversible/cryogenic computing.
• Interconnect delay is a hard constraint: at 10 GHz a cycle is ~0.1 ns, only a few cm of signal travel.
• Newer process nodes reduce capacitance and can shift the “sweet spot” frequency, but gains in clock rate have been tiny since ~2003.

Single-Core Speed vs Parallelism

• Debate over whether 10 GHz is even desirable for everyday workloads.
• One side: modern tasks are multi-threaded; adding cores and SIMD (AVX, GPUs) gives better returns than chasing clocks.
• Counterpoint: “single-thread” or, more precisely, dependent-operation performance still matters; only higher frequency really helps long dependency chains.
• SIMD/vector/matrix units are called out as parallelism, not true single-thread latency improvement; they shine only with many independent operations.

Other Performance Breakthroughs

• Many say the HDD→SSD transition was a bigger real-world leap than any CPU clock bump after the MHz wars.
• Dedicated GPUs and later high core-count CPUs (Threadripper, etc.) gave huge speedups for specific workloads like games, compiling, and data processing.
• Apple’s M1/M2 laptops are often cited as the first “wow” upgrade since SSDs, mainly for power efficiency and quietness, though not matching top desktop GPUs.

Historical Context: Athlon and Intel

• The 1 GHz milestone is seen as mostly marketing; its real importance was AMD beating Intel and offering better IPC (especially in floating point).
• The Pentium 4’s high clocks are described as “cheating” via very long pipelines and low IPC; Intel originally talked about 10 GHz but hit a wall.
• Intel later retreated to Pentium III–derived cores (Pentium M → Core → modern Core) and adopted AMD’s x86‑64, effectively abandoning the NetBurst/Itanium vision.

Software Bloat and User Experience

• Strong sentiment that software (e.g., Electron/JavaScript apps, chat clients) has absorbed decades of hardware gains, sometimes feeling slower than lean 90s equivalents.
• Others distinguish genuine new capabilities (rich media, DAWs, modern games) from pure bloat.
• Overall sense: raw compute has grown massively, but everyday responsiveness often depends more on storage, OS overhead, and software efficiency than GHz.