Currently, ARM is the undisputed leader among makers of “system on chips” or SoCs for smartphones, while Intel has just entered the market. In 2012, Intel had introduced the CloverTrail+ for cell phones. It was a dual core Medfield processor, and it used technology that was present in chips made for computers and laptops in 2008. In comparison, Apple and Samsung have upgraded their chips for smartphones many times over.
The chips used as processors in cell phones are much different from those used in laptops. The chips in smartphones have different I/O functions, manufacturing nodes, and screen technologies, to name a few. ARM has been successful so far because of its low power chip design.
On the other hand, Intel had been away from the smartphone market till recently. ARM ruled the roost with its RISC ISA, which uses less power for processing. The Cortex-A 15 is one of the most popular ARM chips, and it is used in high profile devices like the Samsung Galaxy S4, and the Nexus Tablet. To get a better footing in the market, Intel is introducing the Silvermont Atom processor for the smartphone market. It uses the x86 ISA which is slightly more complicated than the ARM processors.
Even before the launch of the Silvermont Atom, Intel claimed that the Cortex-A 15 has high power consumption and low performance which makes Silvermont Atom much ahead of the ARM processor. In retaliation, ARM states that their analysis revealed that their processors were a generation ahead and hence would continue to do well.
What Is Essential For A Smartphone Chip?
Smartphone chips have different uses for different devices. For low cost phones, the aim is to have the smallest possible chip with standard performance. This is done by maximizing mW/mm2. A producer of low cost devices would value a reduction in size more than an increase in performance. On the other hand, high cost products would value higher performance without overstepping the thermal limit of 4W or less.
ARM processors usually provide maximum performance at an energy expense of 700mW, notwithstanding the energy required for large cache processes. Therefore, the Cortex A 15 works perfectly well with tablets and high quality cell phones. It works on a 28nm process, and toes the threshold for power consumption. On the other hand, the Cortex-A 7 is a smaller and less powerful processor. Hence, as the performance of a chip increases, it has been seen that the mW/mm2 reduces.
The performance of the Cortex-A 15 can be charted by checking the throughput v/s energy graph. However, this cannot be checked for the Intel Silvermont Atom because the product is not yet available in the market. It has been claimed that the new chip can save up to 5x time energy when the phone is lying idle and increase 3x performance when it is being used, compared to the Saltwell Atom processor “Clover Trail +” available in the market.
Reports Fuelling The Competition
Certain reports, like the one from ABI research, have claimed that the Intel Clover Trail+ chips have been outperforming those of ARM. The Clover Trail + technology apparently outdid the Qualcomm APQ8064T and Samsung Exynos Octa in the tests conducted. ARM is the design partner for chip manufacturer Qualcomm. In the tests, it was seen that the power consumption by Intel chips were 60% lesser than the Exynos Octa, and 47% lesser than the Qualcomm ones. This was a blow to the claims made by ARM that their chips were most power efficient and provided good performance. The Lenovo K800 which uses Intel’s Clover Trail + was used in the test. This cell phone was pitted against phones using other chips.
On investigation of the report, it has been seen that different versions of the AnTuTu benchmark was used. When the versions were changed from 2.9.3 to 3.3, the performance change for Intel was 122% while that for Samsung was 59%. Therefore, version 3.3 worked better on Intel Hardware compared to the others. The switchover allowed Intel to skip some instructions of the RAM performance test, which made it perform better. To conclude, the change in scores was only due to a change in the versions of the test and not because of the hardware used. The claim made by the report turned out to be biased because it was not tested on all parameters or on different platforms.
How Does One Know About The Efficiency Of Smartphone Chips?
Much like the case with PCs, it is not possible to accurately measure which processor is better. In case of PCs and Laptops, it is seen that certain applications work well on one set of processors and not so well on another. The same thing can be seen in case of smartphones as well. Certain applications will adapt better with ARM’s processors while others will find favour with Intel.
Till some set parameters or tests are devised, it would be very difficult to comment on the performance of a processing chip.
Who Will Be Ahead Of Whom?
ARM, being the incumbent, has a lot of advantage over Intel. Its technology has been tested, and it has found favour with a number of manufacturers. Intel smartphones
on the other hand will have to prove that it is at least as good as ARM.
ARM runs an R&D service which constantly innovates the chip design. It has partnered with some of the most popular chip manufacturers like Nvidia and Mediatek. These manufacturers take on the ARM IP, and build it into numerous SoCs. ARM is now devising a new chip, the Cortex-A 57, which will provide faster performance and more energy efficient technology.