The number of compute Units on the APU were doubled in PlayStation 4 .
The number of graphics Compute Units on the APU was doubled to 36 Graphics Core Next ( GCN ) Compute Units ( from 18 ) , with a clock speed increase to 911 MHz ( from 800 MHz ) , resulting in a theoretical single precision floating point performance metric of 4.2 TeraFLOPs .
PlayStation 4 technical specifications