At a presentation at the Game Developers Conference today, Sony Senior Staff Engineer Chris Norden went into greater technical detail on some of the PlayStation 4's underlying hardware, including the PS4 Eye depth sensing camera. While all of this information is not finalized and subject to change, the presentation gave us our deepest look yet at Sony's next generation of console hardware.

Norden started by focusing on the chips, including the 64-bit x86 CPU that he stressed provided low power consumption and heat. The eight cores are capable of running eight hardware threads, with each core using a 32KiB L1 I-cache and D-cache, and each four-core group sharing 2MiB of L2 Cache. The processor will be able to handle things like atomics, threads, fibers, and ULTs, with out-of-order execution and advanced ISA.

Sony is building its CPU on what it's calling an extended DirectX 11.1+ feature set, including extra debugging support that is not available on PC platforms. This system will also give developers more direct access to the shader pipeline than they had on the PS3 or through DirectX itself. "This is access you're not used to getting on the PC, and as a result you can do a lot more cool things and have a lot more access to the power of the system," Norden said. A low-level API will also let coders talk directly with the hardware in a way that's "much lower-level than DirectX and OpenGL," but still not quite at the driver level.

The system is also set up to run graphics and computational code synchronously, without suspending one to run the other. Norden says that Sony has worked to carefully balance the two processors to provide maximum graphics power of 1.843 teraFLOPS at an 800Mhz clock speed while still leaving enough room for computational tasks. The GPU will also be able to run arbitrary code, allowing developers to run hundreds or thousands of parallelized tasks with full access to the system's 8GB of unified memory.

Speaking of memory, Norden hyped up the 8GB of GDDR5 RAM in the system as the type of memory that's currently usually found only on high-end graphics cards. Calling the RAM "expensive" and "exotic," Norden stressed that you "can't buy this [RAM] for 50 bucks... that's why high-end graphics cards cost as much as they do." The 176 gigabytes of total bandwidth provided by that GDDR5 RAM are much more efficient than the 40 gigabytes a second provided by the standard DDR3 RAM used in most current computer systems. The unified address space should also cause fewer headaches for developers than the mixed architecture of the PS3, Norden said.

The development environment coders will use is based on Windows 7 and fully integrated with Visual Studio 2010 and 2012, allowing developers to debug PS4 code just like PC code. Tools will include C and C++ front ends that are largely compatible with most standard compilers, and various binary utilities, including CPU and GPU analyzers that can run in real time alongside games. Development houses will also be able to distribute tool and version updates to multiple dev kits more easily through a tool integrated into Windows Explorer.

As for the physical hardware itself, the PS4 will have a Blu-ray drive that's "up to three times faster" than the PS3's drive and will include a "very large" hard drive in every system.

DualShock 4

The DualShock 4 controller that's standard on the PS4 eliminates one feature that was seldom used on the PS3—the analog face buttons and d-pad. While games like Gran Turismo 4 made use of this feature, most developers ignored it. Using digital face buttons on the DualShock 4 will allow Sony to "cut latency way down" for the new controller, Norden said.

For force feedback technology, the DualShock 4 has one small motor and one large motor, much like the DualShock 3. The new controller will let developers vary the analog strength of each motor, though, unlike the digital motors on the PS3, allowing for "more precise, cool effects."

The L2 and R2 buttons on the Dual Shock 4 have been redesigned to be more comfortable and to ignore accidental pressure when players place the controller down on a coffee table, for instance. The analog sticks have also been tightened, Norden said, for a reduced dead zone and better feeling tension that grips your thumbs. The touchpad on the controller will allow for two points of recognition at a 1920×900 resolution, which is pretty large considering the small size of the pad.

Norden also highlighted the light bar on the back of each DualShock 4 controller. The full-range RGB LEDs in each controller will light up blue, red, pink, and green to correspond to players 1, 2, 3, and 4, respectively. The lights will also blink when the controllers are charging (which is now possible even when they are plugged into a PS4 system in standby mode) and turn off when the charging is complete.

Finally, the PS4 will include a mono headset and microphone in every box that plugs directly into the DualShock 4. The system is capable of streaming 32Khz sound to the controllers' speakers for up to 2 players, but that reduces to 16Khz when 3 or more players are hooked up.

PlayStation 4 Eye camera

The PS4 Eye seems like a significant upgrade from the normal PlayStation Eye that was used on the PS3. The two cameras inside the unit are each capable of 1280×800 resolution and 60Hz at a color depth of 12 bits per pixel. That resolution can actually be turned down to increase the response rate, so a resolution of 640×400 would get you an extremely fast 120Hz measurement. The camera's 85 degree field of view means that there will be fewer out-of-range problems with PlayStation Eye games, Norden said, while a four-mic camera array can provide directional listening capabilities.

Norden highlighted the PS4 Eye's ability to change things like exposure, white balance, and gain per camera or per frame, unlike the "one image" original PlayStation Eye. This can allow a developer to, for example, use one camera at low exposure to track the bright PlayStation Move balls, and the other at higher exposure to show a player that would otherwise look dark in a dimly lit living room.

The camera itself actually sports its own three-axis accelerometer, which Norden noted can be used to remind the player to change the orientation if it's not pointed correctly. In addition, the camera can be synced with the "game loop" clock so that images of players line up with the in-game action without lag.

In a quick filmed demo, Norden showed users flicking the touchpad on the DualShock 4 to create an augmented reality menu that moved along with the controller in the player's hands, and a modified pong game where the position of the players' controllers caused the playfield to move, morph, and bend. The cutest demo, though, featured a number of tiny robots trapped inside a virtual DualShock 4 controller, getting flicked out into an extremely sharp and responsive augmented reality environment as the player flicked the touchpad.

User Interface

Finally, Norden went in to a little more detail on the PS4's user interface. The system will be focused on providing users up-to-date information on all their games from a central menu, telling them about things like new DLC, social recommendations, and videos without having to boot up a game. The default home screen will provide a digest view of everything happening on a player's PS4 social network, displayed by default at boot up. The friends system has also been improved from the PS3, allowing for a higher maximum number of friends and improved multi-user support when a few PSN users are playing on one system.

Norden highlighted that the PS4 will use a dual identification system that uses both a "True Name" and picture alongside a PSN name and avatar. Your True Name will only be visible to friends that you add through Facebook or through True Name search, Norden said. Otherwise, both users have to mutually agree to share their True Names to see them. "It's kind of up to you how you want people to access your True Name" he said.

Sony also hopes that developers will integrate social features directly into traditionally single-player games. Norden gave an example of a Heavy Rain scene, where a decision between discussing something with your son or getting a snack was accompanied by a pop-up display showing how many of your friends chose each option.

To wrap up, Norden discussed the extra PS4 chip that allows for a constant storage of the last few minutes of video of your gameplay, without taking away power from the core CPU or GPU. This allows for easy sharing of awesome moments without advance planning, Norden said. It also allows for live streaming and spectating of every PS4 game without extra developer support, and for Remote Play on the PlayStation Vita, with a mirrored display that makes use of the system's full 960×554 resolution. That Remote Play will be possible over either a home network or the Internet, but the latter will obviously be highly dependent on bandwidth and latency, Norden said.