1980s, the new RISC designs were easily outperforming all traditional designs by a wide margin. At that point, all of the other vendors began RISC efforts of their own. Among these were the DEC Alpha, AMD Am29000, Intel i860 and i960, Motorola 88000, IBM POWER, and, slightly later, the IBM/Apple/Motorola PowerPC. Many of these have since disappeared due to them often offering no competitive advantage over others of the same era. Those that remain are often used only in niche markets or as parts of other systems; only SPARC and POWER have any significant remaining market. The outlier is the ARM, who, in partnership with Apple, developed a low-power design and then specialized in that market, which at the time was a niche. With the rise in mobile computing, especially after the introduction of the iPhone, ARM became the most widely used high-end CPU design in the market. Competition between RISC and conventional CISC approaches was also the subject of theoretical analysis in the early 1980s, leading, for example, to the iron law of processor performance. Since 2010 a new open source instruction set architecture (ISA), RISC-V, has been under development at the University of California, Berkeley, for research purposes and as a free alternative to proprietary ISAs. As of 2014, version 2 of the user space ISA is fixed. The ISA is designed to be extensible from a barebones core sufficient for a small embedded processor to supercomputer and cloud computing use with standard and chip designer–defined extensions and coprocessors. It has been tested in silicon design with the ROCKET SoC, which is also available as an open-source processor generator in the CHISEL language. Characteristics and design philosophy Instruction set philosophy A common misunderstanding of the phrase "reduced instruction set computer" is that instructions are simply eliminated, resulting in a smaller set of instructions. In fact, over the years, RISC instruction sets have grown in size, and today many of them have a larger set of instructions than many CISC CPUs. Some RISC processors such as the PowerPC have instruction sets as large as the CISC IBM System/370, for example; conversely, the DEC PDP-8—clearly a CISC CPU because many of its instructions involve multiple memory accesses—has only 8 basic instructions and a few extended instructions. The term "reduced" in that phrase was intended to describe the fact that the amount of work any single instruction accomplishes is reduced—at most