Why does ARM have such low power consumption?

The reason why ARM has low power consumption is that its out-of-order execution capability is not as good as X86. In other words, when a user is using a computer, his operations are random and unpredictable, which makes the instructions unpredictable. In order to enhance the processing capability in this situation, X86 has strengthened the execution of out-of-order instructions and enhanced the multi-threading capability of a single core. The disadvantage of this is that it is impossible to effectively shut down and restore the processor sub-modules, because once shut down, the recovery is very slow. In order to maintain high performance, most modules have to be kept turned on and the clock must be switched at a high speed. The direct consequence is high power consumption. ARM's RISC instruction optimization is strong in determining the order of execution, and relies on multi-core rather than single-core multi-threading to execute, which makes it easy to keep sub-modules and clock signals closed, which is obviously more power-saving. In addition, in the operating system

At the same time, many threads are usually opened on personal computers. Mobile platforms usually only keep necessary threads. This further widens the power consumption gap. Of course, if X86 is used on mobile platforms, it will definitely save power because of fewer threads. Now INTEL's ATOM is specially optimized for these features, which can reduce the processing power of out-of-order execution and multi-threading to a certain extent, and can also achieve a TDP of 1W and a power consumption level of 250mV in daily work. In addition, 1. CISC and RISC must be RISC in terms of efficiency. In fact, the current INTEL and AMD processors themselves also use a RISC-like core plus a CISC interpreter structure. 2. The latest quad-core ARM Cortex A15 is actually not a quad-core, but two A15 cores plus two low-power M5 cores. If it is a pure A15 core, the performance is estimated to be about 18,000 DMIPS, while INTEL's CORE 2 DUO E6600 dual-core can reach more than 29,000 DMIPS at 2.4Ghz, which is close to the A15 standard operating frequency of 2.5Ghz. 3. You cannot develop IOS programs on Windows. The main reason is that there is no Windows version of the development software, and the compilation is not possible. You must rely on LINUX. As for ANDROID, there is an SDK for development, but the source code cannot be compiled. 4. There is currently no completely identical software for the two. X86 does not need to be ported to ARM. If ARM ports X86 software, an interpreter is required, so the size is larger.