When Samsung announced their latest Exynos octa-core chipset, the Exynos 5420, everyone naturally assumed it would be powering the Galaxy Note 3. However, Samsung didn't exactly mention it officially, but an image sent to us by a tipster confirms that it is indeed the Exynos 5420 powering Samsung's latest, and perhaps greatest, phablet. The screenshot shows the app CPU-Z running on the SM-N900 (the octa-core model), and it also reveals that the usable RAM out of the total 3GB will be 2720MB.
However, it looks like the Galaxy Note 3 and all its whiz-bang features might be memory hogs, as the available RAM in the screenshot is only 392MB, though that's hopefully with a lot of apps and services in the background. Also, there might be a slight possibility that Chinese models will have 16GB of storage as minimum – the device in the screenshot shows a 16GB variant and is running on a Chinese firmware (ZSUBMI5), and the recently leaked dual SIM model for China also had the same internal storage. These could also be just test models, but we'll need to wait for official info to make sure.
But there you have it, the Galaxy Note 3 is powered by the Exynos 5420, which might also get a software update later on to enable use of all eight CPU cores at once.