PX6 processor (RK3399)

Known as PX6 or RK3399

When searching for an Android Headunit for your vehicle, you often come across cryptic definitions and ‘RK3399’ is just one of those.

RK3399 is listed as ‘Processor’ and you will often see ‘PX6’ in the same description, but what is the difference and why do they show both? Is one part of the other or is one an upgrade? Do I need both to get a good android headunit?

RK3399 is a SoC

SoC is a System on a chip – by Rockchip – hence the RK designation and why it is often called a processor. Advertising pitches often refer to its a PX6 because it is easier to portray.

Cortex Cores

Rockchip have produced many SoC systems based on the various Cortex cores. The RK3399 is made up of two Cortex-A72 and four Cortex-A53 in big.LITTLE hexacore configuration. This is exactly the same as the PX6. In fact the PX6 is the RK3399 in another name. They are the same processors (Soc) but the PX6 sounds better in the advertising material when next to an octacore PX5.

Everyone sees that ‘6’ is better than ‘5’.

When the sales team want to write copy that gets the message across then you can’t beat adding +1 to show it is the next generation. We have all seen Android 10 being touted as better than Android 9. The same sales pitch applies.

The RK3399 is the PX6. It is the same thing, just by a different name. If you are looking for an android headunit then a PX6 or RK3399 would be a good choice as the SoC Processor to power it.

PX6 in depth

The hexacore PX6 is made up of a dual-core ARM Cortex-A72 MPCore processor and Quad-core ARM Cortex-A53 MPCore processor. Both of these MPCores are high-performance, low-power and cached application processors.

The PX6 configuration is by two CPU clusters. There is one ‘Big’ cluster with a dual-core Cortex-A72 that is optimised for high-performance. The other CPU cluster is the ‘little’ cluster. With quad-core Cortex-A53 this little cluster is optimised for low power.

PX6 RK3399 has full implementation of the ARM architecture v8-A instruction set.

The PX6 frequency is clocked at just over 1.8GHz for the BIGcluster.

PX6 Block Diagram

PX6 Block Diagram


Integrated within each PX6 CPU cluster is the ARM Neon co-processor (FPU). The neon has Advanced SIMD (single instruction, multiple data) support. This FPU benefits the android headunit by accelerating media and signal processing, audio and video encoding and decoding, user interface processing and 2D/3D graphics.

PX6 Graphics

The PX6 Graphics Processing Unit (GPU) provides a complete 2D and 3D graphics acceleration platform based on open standards.

The PX6 GPU supports the following graphics standards:

  • OpenGL ES 3.0
  • OpenGL ES 2.0
  • OpenGL ES 1.1
  • OpenCL 1.2
  • OpenCL 1.1
  • OpenCL 1.0
  • DirectX 11.1
  • DirectX 9

The PX6 GPU consists of:

  • 4 Shader Cores
  • 1 256KB Level2 Cache Memory Subsystem
  • 1 Memory Management Unit
  • 1 Job Manager
  • 1 Hierarchical Tiler
  • 1 Core Group


PX6 (RK3366) is compatible with DDR3-1866 /DDR3L-1866 /LPDDR3-1866 /LPDDR4 SDRAM. This is an improvement over the PX5 processor and inline with the normal memory speed timing improvements over time. The faster ARM cores need faster RAM to keep the work processing work flowing, so faster RAM can be used.


We are seeing support for USB3.0 in the later processors like the PX6. Expect android headunits to be supporting USB3 and USB3OTG as these next generation processors become more widely used.

Overall PX6

The PX6 processor for an android head unit is a breath of fresh air. No more is there any need to re-purpose the phone chips to run an android headunit. They are getting dedicated processing power. The hexacorePX6 is seen as the successor the quadcore powered PX5. Many of the PX5 android headunits have been upgraded to PX6 power and speed. This took very little work to make the upgrade for manufacturers and as soon as the PX5 units stocks were dry, identical looking PX6 units stepped in.

The new PX6 processor also accelerated the rise in popularity of the quick to boot and fun to use single DIN with a 10.1″ screen android head unit. This very popular format is a winner for many android headunit users due to its large screen, universal single DIN fitting and super quick processor.

PX6 Overtaken

The processing speed of the PX6 used in android head units has been overtaken by the UIS7862 chip but the PX6 still stays a firm favourite with the buyers as UIS7862 foothold needs to expand.

RK3399 SoC for Android Headunits
RK3399 Android Headunit Processor
An android-headunits.com staff blogger. I am a multi-skilled dogs-body and I also make the coffee ☕

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