The card, although retains the name "GeForce GTX 295", same device ID, and is compatible with existing NVIDIA drivers, has two huge innovations put in by ASUS, which go far beyond being yet another overclocked GeForce GTX 295: the company used two G200-350-B3 graphics processors, the same ones that make the GeForce GTX 285.
The GPUs have all the 240 shader processors enabled, and also have the complete 512-bit GDDR3 memory interface enabled. This dual-PCB monstrosity holds 32 memory chips, and 4 GB of total memory (each GPU accesses 2 GB of it). Apart from these, each GPU system uses the same exact clock speeds as the GeForce GTX 285: 648/1476/2400 MHz (core/shader/memory).
The cooler internally has the same basic construction as the reference cooler, it uses a single leaf-blower. ASUS also used slightly longer internal bridges that make more room for third-party coolers, and the likes.
techPowerUp! : http://www.techpowerup.com/95445/ASUS_Designes_Own_Monster_Dual-GTX_285_4_GB_Graphics_Card.html