The HSPA+ version of Samsung Electronics' Galaxy S4 smartphone carries a US$236 bill of materials (BOM), up significantly from the Galaxy S3, due to major upgrades in the display, sensors and application processor, and supporting memory, according to IHS iSuppli.

The HSPA+ S4 with 16GB of NAND flash memory costs US$244 when the US$8.50 manufacturing cost is added in, said IHS. The BOM of the HSPA+ version of the S4 is US$30.40 higher than for the equivalent version of the Galaxy S3, a 15% increase.

"Although its hardware is not radically different from the Galaxy S III introduced in April of 2012, the Samsung Galaxy S4 includes some critical component updates that enhance its functionality as well as its BOM cost," said Vincent Leung, senior analyst for cost benchmarking at IHS. "Among the upgrades are a larger, full high-definition (HD) display; a beefed-up Samsung processor; and a wealth of new sensors that set a record high for the number of such devices in a smartphone design. And despite the larger display and other changes, the Galaxy S4 has roughly the same width and the same ease of handling as the Galaxy S III."

The S4 employs a full-HD active-matrix organic light-emitting diode (AMOLED) display from Samsung Display with a pixel format of 1920 by 1080, IHS revealed. This compares to the 1280 by 720 WXGA resolution display in the S3.

The S4's HD display and touch-screen subsystem is estimated to carry a cost of US$75, up from US$65 for the S3, IHS said. This represents the single largest area of cost increase for the S4 compared to the S3.

"While many brands have released smartphone models using full-HD LCD displays, the S4 represents the first with an AMOLED display at this resolution," said Vinita Jakhanwal, director for small & medium displays at IHS. "Reaching a true pixel density greater than 300ppi has been a challenge for AMOLED display makers. However, Samsung was able to enhance AMOLED display performance by implementing new technologies that also drove up the cost of the display."

For the apps processor in the HSPA+ version of the Galaxy S4, Samsung is believed to be employing an Exynos 5 Octa solution, an eight-core chip using its own design, and manufactured with Samsung's own 28nm process, IHS indicated. This compares to the quad-core Exynos apps processor in the Galaxy S3. The cost of the Galaxy S4's processor is estimated at US$30, compared to US$17.50 for the chip in the Galaxy S3, IHS said.

The Galaxy S4's eight-core Exynos processor uses ARM's big.LITTLE microprocessor architecture, IHS continued. The architecture employs a hybrid approach generally referred to as heterogeneous computing, whereby two central processing units (CPUs) – a quad-core Cortex-A15 CPU and a quad-core Cortex-A7 CPU –are integrated into the same chip.

"With big.LITTLE, there is a computing and power consumption tradeoff, in which less computing-intensive tasks, such as phone calls and social media apps, can be handled by the more power-efficient but slower A7 cores," said Wayne Lam, senior analyst for wireless communications at IHS. "This allows the bigger, more powerful and energy-draining A15 cores to remain idle when they are not needed, preserving battery life. The A15 cores go into action only for more computing-intensive applications, like video gaming or decoding video."

This is a unique approach compared to Nvidia's 4+1 Tegra setup or even Qualcomm's asynchronous Krait-cores in the Snapdragon, where the processing cores are evenly matched, IHS pointed out.

The 4G LTE version of the Galaxy S4 employs a different apps processor and baseband, the Qualcomm Snapdragon 600, a quad-core apps processor and LTE radio solution, IHS said. Samsung had a similar hardware differentiation with the LTE version of the Galaxy S3. Given the different apps processors between the Samsung Exynos-powered S4 and the Qualcomm Snapdragon-powered Galaxy S4, some variances in the software capabilities and application performance for the two models are expected. However, that has yet to be verified by Samsung, IHS added.

With its emphasis on detecting and adapting to consumer lifestyles, the Galaxy S4 integrates an array of different sensors, including the accelerometer, RGB light, geomagnetic, proximity, gyroscope, barometer, IR gesture and even temperature and humidity varieties, according to IHS.

The humidity and temperature sensor as well as the IR gesture sensor are new in the Galaxy S4 compared to the Galaxy S3, IHS noted. Because of these new capabilities, the user interface and sensor subsystem of the Galaxy S4 carries an estimated cost of US$16, up from US$12.70 in the Galaxy S3.

Although the LTE version of the Galaxy S4 employs a more advanced mobile radio than the HSPA+ version, its total BOM cost is slightly lower, at US$233.00, IHS indicated.

The LTE Galaxy S4's wireless section costs US$25.00, higher than the US$16.00 for the HSPA+, because it supports the new 4G LTE air interface standard as well as up to six global LTE bands. However, the LTE version keeps expenditures down by using the Qualcomm Snapdragon 600 solution, which costs US$20.00. An additional cost benefit of using the Qualcomm Snapdragon 600 solution comes from the use of a lower-cost wireless LAN/Bluetooth/FM/GPS subsystem.

Samsung makes extensive use of its own internally manufactured parts in all of its phones, including the Galaxy S4, IHS said. The company is believed to supply the display and touch-screen module, as well as the apps processor and power management IC. Samsung also is the primary supplier of the SDRAM and flash memory, although the company could employ alternative sources for these commodity parts, IHS noted.

All told, Samsung accounts for at least US$149 worth of component content in the HSPA+ version of the Galaxy S4, representing 63% of the total BOM, based on the results of IHS' virtual teardown.

Intel is believed to be the supplier of the baseband processor and RF transceiver in the HSPA+ version of the Galaxy S4, just as it did for the Galaxy S3, IHS said. Broadcom is the likely source for the Wireless LAN/Bluetooth/FM/GPS subsystem and the GPS/GLONASS section in the non-Qualcomm variant of the Galaxy S4.