VGLeaks claims to have leaked the first 'real' and full next-gen Xbox specifications and details of the system overview with the general components and some technical details about them. The processor has x64 architecture and eight cores running at 1.6 GHz. Each of those CPU threads has its own 32 kB L1 instruction cache and 32 kB L1 data cache. Each module of the four CPU cores has its own 2 MB L2 cache giving the processor a total of 4 MB of L2 cache. VGLeaks also reports that each core has one fully independent hardware thread and doesn't share execution resources.

Each hardware thread is also reportedly able to issue two instructions per clock cycle. The next-generation Xbox GPU is reportedly a custom D3D 11.1 class unit running at 800 MHz with 12 shader cores and 768 total threads. The machine is also paired with a 6x Blu-ray drive, gigabit Ethernet, Wi-Fi, Wi-Fi Direct, and various hardware accelerators for image, video, and audio codec.

CPU:

x64 Architecture
8 CPU cores running at 1.6 gigahertz (GHz)
each CPU thread has its own 32 KB L1 instruction cache and 32 KB L1 data cache
each module of four CPU cores has a 2 MB L2 cache resulting in a total of 4 MB of L2 cache
each core has one fully independent hardware thread with no shared execution resources
each hardware thread can issue two instructions per clock
GPU:

custom D3D11.1 class 800-MHz graphics processor
12 shader cores providing a total of 768 threads
each thread can perform one scalar multiplication and addition operation (MADD) per clock cycle
at peak performance, the GPU can effectively issue 1.2 trillion floating-point operations per second
High-fidelity Natural User Interface (NUI) sensor is always present
Storage and Memory:

8 gigabyte (GB) of RAM DDR3 (68 GB/s)
32 MB of fast embedded SRAM (ESRAM) (102 GB/s)
from the GPU’s perspective the bandwidths of system memory and ESRAM are parallel providing combined peak bandwidth of 170 GB/sec.
Hard drive is always present
50 GB 6x Blu-ray Disc drive
Networking:

Gigabit Ethernet
Wi-Fi and Wi-Fi Direct
Hardware Accelerators:

Move engines
Image, video, and audio codecs
Kinect multichannel echo cancellation (MEC) hardware
Cryptography engines for encryption and decryption, and hashing.

Désolé pour l'anglais.