Robert Pogson

John Stokes wrote:”It’s also the case that as ARM moves up the performance ladder, it will necessarily start to drop in terms of power efficiency. Again, there is no magic pixie dust here, and the impact of the ISA alone on power consumption in processors that draw many tens of watts is negligible.”

Some people just don’t get it. x86 is taking tens of watts to make a box. I have three in my home running Atom. I know what I have and how much heat they dissipate. ARM can provide the user wonderful performance with less silicon, fewer transistors. “The Cortex-A9 power-optimized hard macro implementation delivers its peak performance of 4000 DMIPS while consuming less than 250mW per CPU when selected from typical silicon.” That was for 40nm. They have 20nm parts scheduled for this year and 14nm is in the pipes.

That’s not magic pixie dust. With a smaller and simpler instruction set, ARM takes fewer transistors to get the job done. ARM cores at the same resolution as Intel Atoms are 4 times smaller in area. x86 has bloated its instruction set over the years and Intel cannot escape it with the huge installed base. ARM does not have that burden. Intel can reduce its power/MIPS ratio with Moore’s Law but ARM is no slouch. It has partners at TSMC and IBM that are headed for 20nm and 14nm production so ARM will always be ahead in that. When both x86 and ARM reach the point of vanishing returns in that power consumption is not an issue, ARM will have a large share of personal computing markets. Further, even when power/MIPS is not an issue, size, price and total power consumption will still matter in data centres which are growing in importance.

Now, this is mostly about mobile computing but that is more than half of all personal computing so ARM has plenty of room to grow. Notebooks are about 60% of unit shipments of non-ARM PCs at the moment and ARMed smartphones and tablets should catch up to the unit shipments of notebooks in a year or so. So, performance per watt does matter and ARM will take a huge share. Some people are used to keeping their notebooks plugged in so x86 won’t suddenly be gone but even the smartphone now meets all computing needs of much of the market for personal computing devices. That will only grow and docks and connectors will take care of more of the need for desktop computing. There will just be no more need for big box/hair-drying PCs in our homes and offices except for content generators and number crunchers. All the heavy work will be done on servers and servers will be far fewer in number than PCs. ARM will take over the computing space just as they have the embedded space.

Did we mention price? With volume production, the price of ARM CPUs will always be less than x86. Less silicon and lower licensing fees means lower prices.