GeForce GTX 590 3GB Specifications

The GTX 590 3GB is equipped with two full size GF110 GPUs. As each has the maximum amount of 512 stream processors possible with the Fermi architecture, this means the GTX 590 3GB boasts a whopping count of 1,024 stream processors. With a core frequency of 607MHz, these stream processors run at 1,214MHz. Both these clock speeds are roughly 20 per cent less than those of the GTX 580 1.5GB.

The use of two full-specification GF110 GPUs also means the GTX 590 3GB boasts eight rasterisers, (2 x 4) and 32 tessellation units (2 x 16). It also sports 120 texture units (2 x 60) and 96 ROPs (2 x 48).

Meanwhile, the 3GB of GDDR5 memory is split between the two GPUs, so each GPU can still only address 1.5GB. The memory is clocked at 853MHz (3,414MHz effective), which is roughly 16 per cent lower than that of the GTX 580 1.5GB and 10 per cent lower than the GTX 570 1.3GB's RAM. The card has a combined memory bandwidth of 327.8GB/sec (2x 163.9GB/sec), running via dual 384-bit memory interfaces.

Certainly on paper it’s a tremendously capable graphics system, with the might of two full GF110 Fermi GPUs offering huge amounts of graphics potential. The fact that Nvidia has clocked the card down quite considerably in comparison to the GTX 580 1.5GB does mean that the GTX 590 3GB won’t be twice as fast as its top single-GPU offering, though. 
source: www.bit-tech.net