Hi Tech Legion posted a review on the ASUS GeForce GTX 660 DirectCU II Top OC Edition graphics card

Titan accomplishes amazing computation speeds by harnessing the power of CPUs and GPU accelerators working in a “symbiotic” relationship. The CPUs work to break the problems into smaller threads that can then be loaded on to the GPUs more power efficient and high speed calculations. The Nvidia Telsa K20 GPUs used to power Titan use a different GPU chip, but utilize the same Kepler architecture as their gaming counterpart. The lower end Telsa K10 actually uses the same GK104 GPU as the GeForce the GTX 690, 680, and 670 graphics cards. While the GeForce GTX 660 uses the GK106 GPU to provide a powerful, energy efficient graphics card.

The ASUS GeForce GTX 660 DirectCU TOP graphics card pushes the boost clock speed from the reference speed of 1033 MHz to 1085 MHz. The ASUS GTX 660 utilizes the Nvidia GK106 GPU core and features 2GB of GDDR5 memory. Memory is clocked at 6008 MHz effectively and supported by three memory controllers creating a 192-bit memory bus. The GK106 core features five SMX units housing a total of 960 CUDA cores and 80 texture units. ASUS further refines the GTX 660 by applying a custom cooling solution, utilizing direct contact copper heatpipes to dissipate heat more efficiently. On top of the custom cooling solution is the DIGI VRM+ power design that ASUS uses with their cards, providing better voltage control and stability.

  ASUS GeForce GTX 660 DirectCU II Top OC Edition Review