5-GHz CPUs are should soon be on store shelves, according to chipmakers at a conference in Silicon Valley this week.

Chip-making advances announced at the SPIE Microlithography Conference in San Jose, California, showed that Moore's Law is alive and well. Moore's Law dictates that chip densities double every 18 months, leading to smaller chips with double the processing power. But the Law has become doubtful lately as lithography and other chip-making processes butt up against the limits of physics. Naysayers say the chip industry has shrunk chips about as far as they can go.

But IBM, for example, said this week it will defy "conventional wisdom" and print circuits with 30-nanometer ridges, a third of the size of the 90-nm chips in production today, using current lithography imaging processes. Also this week, Dutch-based lithography equipment maker ASML Holding NV demonstrated its 42-nm production process and said it had the equipment to make 35-nm chips.

Both developments followed CPU-giant Intel's announcement last month that it had produced a 45-nm SRAM, or Static Random Access Memory, chip.

Shrinking chip ridges below today's 90-nm sizes means PCs in the near future will likely offer performance jumps equivalent to those achieved through the last 20 years (remember when a system with a 468-MHz Pentium and 64M of DRAM was considered a high-end PC?)

According to chipmakers and a technology road map from the Semiconductor Industry Association, we can expect transistor counts on CPUs to double from 1 billion to 2 billion in two years, and to an astonishing 4 billion in four years. The SIA roadmap predicts chips will continue to become smaller and denser through 2020.

Intel and AMD have said CPU clock speeds -- measured in gigahertz -- will not increase to the same degree as in years past due to constraints in power consumption and heat. However, the companies will take advantage of increasing chip densities to pack multiple cores onto each chip, resulting in performance leaps. Intel said there may be as many as 100 cores packed on a single processor within 10 years.

While CPUs with 5-GHz clock speeds in four years is probable, analyst Nathan Brookwood of Insight64 agreed that performance boosts on levels commensurate with years past will be based on multi-core CPU designs.

Also, the amount of DRAM per chip should continue to double from a maximum of 1 Gigabit now to 4 Gigabits per chip in four years, according to memory chipmakers and the SIA roadmap. As DDR2 memory designs become increasingly available now for 1-Gb DRAM chips, it is possible to pack in modules with high-end motherboards that can handle more than four GB of DRAM. With the advent of 2-Gb memory chips in less than two years, 4-Gb devices are expected to follow in four years.