Geforce GTX 680 looks very much like its predecessor, GTX 580. However, a more detailed inspection reveals several important differences.
Looking at the front, we see that the cooler is blower-style and that the fan was placed towards the top of the card rather than dead center. Once we removed the cooler, we saw that the voltage regulation circuitry was placed horizontally in the lower part of the card, rather than vertically like on GTX 580 cards. It could be that the part of the cooler towards the GPU doesn’t get as hot this way. The cooler was designed to cool the GPU, memory and voltage regulation circuitry at the same time.
The GTX 680 is powered via two 6-pin power connectors. It’s interesting to see that Nvidia opted on stacked power connectors. We personally don’t like this as it makes the task of connecting cables much harder. When disconnecting the cables, you’ll have to take out the bottom one first and then the top one, which was rotated by 180 degrees.
We already said that Nvidia implemented a type of auto-overclocking (GPU Boost), which monitors consumption and TDP and then changes clocks on the fly in order to maximize performance. Monitoring consumption come courtesy of the three INA219 power monitor chips (two for 6-pin power connectors and one for PCI-Express consumption).
The memory is faster than ever before, which means Nvidia solved some important issues in this respect. The GTX 680 comes with 2GB GDDR5 memory that runs at 1502MHz (6008 MHZ GDDR5 effectively). The chips on Gainward’s card are made by Hynix, and carry the model number H5GQ2H24MFR-R0C. They are specified to run at 1500 MHz (6000 MHz GDDR5 effective).
The card has a dual-link DVI port (with analog VGA), one dual-link DVI port (digital only), one standard HDMI and DisplayPort. Thanks to Nvidia’s new display output logic, Kepler based cards can support up to four displays.
The card is 25,6cm long, whereas last top models like the HD 7970 or GTX 570/580 are 27 long. Just like all high-end cards, Gainward’s GTX 680 allows for chaining up one or two more Geforce GTX 680 cards, in order to get more performance (for 3D Stereo Vision now is enought to have just one GTX 680 graphics card).