The Apple logo.
IN PHOTO: The Apple logo is pictured at a retail store in the Marina neighborhood in San Francisco, California April 23, 2014. REUTERS / Robert Galbraith

Apple is believed to likely reserve its major handset bump ups for the iPhone 7 but for the iPhone 6S that is rumoured for release date in the second half of 2015, the purported upgrades are nothing short of the usual killer features.

And going by the latest buzz making the rounds on the Apple sphere, the next iPhone from the tech giant will boast of at least three fresh functionalities.

Twice the RAM bandwidth

Even as the S phase, in which the iPhone 6S will expectedly fall, is generally viewed as incremental step up for Apple's flagship smartphone, the latest supply chain news from Asia, where the device is assembled, indicates of a huge RAM upgrade.

From the LPDDR3 that came with the iPhone 6, the 6S is rumoured to sport a RAM chip in the LPDDR4 class, according to tech blog site G4Games. The report points to Taiwan-based Tech News as source.

The main benefit of the RAM jump is the 6S will gain twice the RAM bandwidth of its predecessor plus the significant bonus of better use of battery juice.

It was also suggested that from the 1GB RAM that Apple had provided for the iPhone 6 last year, the upcoming provision can go as high as 2GB, again positioning the 2015 iPhone in a great advantage over its rival Android and Windows flagship.

Dual-lens shooter

In the iPhone 6 and especially in the case of the bigger 6 Plus, Apple has reaped praises for the killer camera packed with the devices. The same is expected for the sequel and more. According to Apple Insider, the 6S shooter is destined to be equipped with dual-lens though no specific supplier was mentioned by the tech site's sources.

With the likely camera improvement, Apple fans will get to experience optical zoom features, which the report noted is a first for the iOS-powered smartphone.

Also, iPhone users can expect to capture better quality images even on low-light situation as dual-lens module will allow the camera sensor to take in as much light as possible, Apple Insider added on its report.

iPhone joystick

Perhaps the most interesting addition for this year's iPhone is a joystick controller that according to Business Insider has also the least chance of making the 6S final cut.

Should a joystick-like button on the next iPhone materialise, the actual application is both exciting and enjoyable. Gaming on the device will reach new level and more.

"It's a unique idea that could have other applications: maybe the joystick would be able to control some camera functions, or you could use it to control drones or other Bluetooth-enabled accessories," said the same Business Insider report that points to Patently Apple as source.

However, joystick on the next iPhone will entail a major hardware revamp of the iconic iPhone home button, which recently had an overhaul when Apple introduced the Touch ID fingerprint reader with the iPhone 5S.

That happening in time for the iPhone 6S is likely remote, added the report.

The iPhone 6S release date should take place in the third quarter of the year with Apple possibly picking fall of 2015 as the touchdown moment.