One of the main upgrades to the next iPhone’s internals will be a redesigned wireless system featuring a new Qualcomm-made LTE chip, as revealed by images of a prototype iPhone 6S logic board shared by a source. As shown in the image below, the new device will include Qualcomm’s MDM9635M chip, also known as the ‘9X35’ Gobi modem platform. This new chip promises significant performance improvements over the “9X25” chip found inside of the current iPhone 6 and iPhone 6 Plus, capable of delivering up to twice the theoretical LTE download speeds…

The new MDM9635M chip was first introduced by Qualcomm in late 2013, nearly two years after the chip inside the iPhone 6 and 6 Plus was first announced. However, due to standard production lag times, the chip only hit the smartphone market one year ago, as the modem inside a South Korean variant on Samsung’s Galaxy S5. For end users, the most important new feature from the chip will be the potential for up to 300 Mbps download speeds, doubling the 150 Mbps download speeds found in the current generation iPhone lineup. The new chip has the same 50 Mbps upload speed limit, however, and real-world performance is likely to be closer to 225Mbps or lower, depending on the cellular network.

The newer processor also is more power efficient, according to Qualcomm, which could mean improved battery life when the iPhone 6S is used for LTE functionality. We are also told that the new iPhone’s motherboard is slightly narrower and more compact overall than the iPhone 6’s and iPhone 6 Plus’s motherboard, which could mean extra room for a modestly larger battery. Combined with iOS 9’s new power-saving features and low-power mode, it would make sense for Apple to also improve battery life by way of upgraded hardware.

Qualcomm’s new chip saves Apple some motherboard space due to its slightly more compact size. The “9X35” is built using a newer 20nm production process, more condensed than the 28nm process used for the Qualcomm cellular data chip in the current iPhones. The “9X35” new chip is Qualcomm’s first built with the new production process, which leads to power efficiency and reduced heat generation. This new chip could prevent iPhones from warming up when under intense data usage.

An upgrade over the “Category 4” chipset in the current iPhone, the new chip is in the category of “Category 6” cellular modems due to its speed. “The Category 6 speeds enabled by the Gobi 9×35 will allow customers to enjoy blazing-fast downloads, snappier application performance due to lower network response time, and run more connectivity based applications smoothly, as well as concurrently,” Qualcomm said when discussing the new chip.

It is still “backwards compatible and supports all other major cellular technologies, including DC-HSPA, EVDO Rev. B, CDMA 1x, GSM and TD-SCDMA,” Qualcomm later added. The chip maker also said that the chip enables smartphone makers to “design sleeker devices without sacrificing performance, while at the same time allowing operators to increase their network capacity and efficiency,” which could open up the door for slimmer iPhones in the future.

However, it does not appear that a slimmer iPhone is ready for 2015, as our earlier images indicated no easily discernible external design differences between the upcoming iPhone and the current iPhone line. In addition to more robust wireless networking and potentially improved battery life, we were told in May that the new iPhone will include a Force Touch display akin to that on the Apple Watch. We’re still tracking additional iPhone 6S details this week, so stay tuned.