A Closer Look
NVIDIA's cooler covers both GPUs, the PCI-Express bridge chip, memory and voltage regulation circuitry.
For voltage control the card uses a NCP 4206 controller, this is only the second card I've seen this chip on, so there is no info available online regarding its features.
The PLX PEX8747 connects the two graphics processors to the PCI-Express bus (you may know its siblings with a shiny metal heatspreaders). It's a 48 lane PCI-Express 3.0 switch, which offers massive bandwith, multicast and peer-to-peer communication features.
The GDDR5 memory chips are made by Samsung, and carry the model number K4G20325FD-FC03. They are specified to run at 1500 MHz (6000 MHz GDDR5 effective).
Two NVIDIA GK104 Kepler graphics processors are located on the GTX 690. It is NVIDIA's first chip to be produced on a 28 nanometer process, at TSMC Taiwan. The transistor count is 3.54 billion.