Similar to previous releases, Apple never reveals the full spec sheet of its products, including during its press events as well as product webpages. However, thanks to Hamza Sood, an iOS developer, with the help of Xcode, now we do know that the iPhone 6s and the iPhone 6s Plus feature 2GB of RAM, while the iPad Pro comes wit 4GB of RAM, which is the highest amount of RAM ever installed on both iPhones and iPads.
Unfortunately, there is still no word ye the 3rd-Gen A9 and A9X Chip number of cores as well as clock speed.