If you are taking computer architecture classes, studying electronics, or doing research related to microprocessors, you may have heard of warnings about the end of Moore’s law: microprocessors will soon not be able to double their performance every 18 months for some physical limits related to making transistors smaller and keeping them fairly efficient in power consumption.
Microprocessors depended mainly on three main factors to keep Moore’s law in effect: (1) Reducing transistor size, so that we can have more in the same area with more sophisticated execution logic and be able to fit in more cache, (2) Increasing Transistor frequency, to execute more instructions, and (3) Economics of manufacturing, to keep the next generation of microprocessors affordable to everyone. Right now it is difficult to cram more transistors due to current limits on lithography. Also, as transistors get smaller and operate at higher frequencies, their power consumption is increasing at greater rates than the increase in performance. Finally, the manufacturing cost is increasing astronomically as we move from one generation to another.
I think Moore’s law may not live as it stands right now. The pattern may keep going by through different means. Here is my stab on it:
Reconsidering the execution pipelines to have shorter latency time per instruction.
Increasing the number of cores, which increase the overall throughput. This is possible through making a better use of the total number of transistors that can fit in one chip. It is possible to work since pipelines should be of less depth.
Homogeneity of instructions set and heterogeneity in implementations. For example, a multi-core processor may have 32 cores with same arithmetic and logical operations instructions, but only two or four of them implement other system control instructions, such as protected mode and interrupt handling instructions. Applications may not need radical rewriting in this case. Actually we can automate the process of migrating these traditional multi-threaded applications to this new heterogeneous architecture.