The press release describes the GPU and the memory as:

PS4 is equipped with 8 GB of unified system memory, easing game creation and increasing the richness of content achievable on the platform.  GDDR5 is used for this memory, giving the system 176 GB/second of bandwidth and providing a further boost to graphics performance. The end result for gamers is new games with rich, high-fidelity graphics and deeply immersive experiences that shatter expectations.

The Graphics Processing Unit (GPU) has been enhanced in a number of ways, principally to allow for easier use of the GPU for general purpose computing (GPGPU) such as physics simulation.  The GPU contains a unified array of 18 compute units, which collectively generate 1.84 Teraflops of processing power that can freely be applied to graphics, simulation tasks, or some mixture of the two.

The complete specification is below:

Main Processor 
Single-chip custom processor
CPU :  x86-64 AMD “Jaguar”,  8 cores
GPU : 1.84 TFLOPS,  AMD next-generation Radeon™ based
graphics engine

Memory 
GDDR5 8GB

Hard Disk Drive 
Built-in

Optical Drive
(read only)
BD 6xCAV
DVD 8xCAV
I/O
Super-Speed USB (USB 3.0) 、AUX

Communication 
Ethernet (10BASE-T, 100BASE-TX, 1000BASE-T)
IEEE 802.11 b/g/n
Bluetooth® 2.1 (EDR)

AV output 
HDMI
Analog-AV out
Digital Output (optical)

It is interesting to see the official specs are pretty close to what we reported a  week back. You can red that article over here. The only massive change is the RAM. Sony have learned their lessons and have put in a powerful 8GB GDDR5 RAM, which should make the system future proof for years.

Let us know your thoughts in the comments section below. Stay tuned to for our continuous coverage of the PlayStation 4.