Gigabyte GeForce GTX 780 OC WindForce X3 3GB (GV-N780OC-3GD)
Gigabyte Technology has five GeForce GTX 780 modifications in its model range but two of them are just new revisions of older products. We’ve got a first-revision GV-N780OC-3GD model, which is the fastest that Gigabyte offers.
Unfortunately, we received the card without packaging and accessories, so its pack shot is taken from the official website:
The GeForce GTX 780 OC WindForce X3 is manufactured in China and comes with a 3-year warranty. It sells at $679 in retail.
The card is equipped with a triple-fan cooler that covers its entire face side. With translucent fans and perforated casing, the card doesn’t look bulky.
It measures 292x129x43 mm and has a standard selection of video outputs:
The power and MIO connectors are standard as well:
As opposed to the EVGA, the Gigabyte had no separate cooling plate on the memory chips and power transistors which are cooled by the main heatsink. It was easy to take it off, so we could see a reference PCB once again:
The power system and controller are standard:
The GPU is revision A1. It was manufactured in late March, 10 weeks earlier than the EVGA's chip.
It is clocked at 954/1006 MHz in 3D applications, which is 10.5% higher than the reference card’s clock rates. According to our monitoring data, its frequency peaked up to 1058 MHz at high loads. The ASIC quality of the GPU is 62.1%:
We can see the same GDDR5 memory chips (Samsung K4G20325FD-FC03) as on the EVGA card. The total memory amount is 3 GB.
The memory frequency is standard, so the Gigabyte only differs from the reference GTX 780 in its GPU specs:
The graphics card features Gigabyte’s WindForce X3 cooler which is claimed to be able to dissipate up to 450 watts. That’s more than enough to cope with the 250-watt GeForce GTX 780. And such an ambitious cooler is only two PCIe slots large:
Its heatsink consists of two parts connected with six heat pipes. Four of these pipes are 6 mm in diameter and two, 8 mm. Besides the copper base the heat pipes go out from, an aluminum plate is secured on the main heatsink and contacts with the memory chips via thermal pads. The power components are cooled by a copper plate attached to the auxiliary heatsink.
The heat pipes are soldered to the cooler’s base and to the heatsink fins.
The heatsink is cooled by three 80mm Everflow T128010SU fans (the actual diameter of the impeller is 74 mm).
Their improved sleeve bearing is supposed to last for at least 50,000 hours. Their speed is PWM-regulated in a range of 800 to 4700 RPM.
Tested under the same conditions as the EVGA, the Gigabyte GeForce GTX 780 OC WindForce X3 had the same GPU temperature in the automatic fan regulation mode (74°C). At the maximum speed of 4730 RPM, its GPU was only 61°C hot.
Auto fan mode
Maximum fan speed
In our overclockability tests the Gigabyte GeForce GTX 780 OC WindForce X3 was stable at a 70MHz higher GPU clock rate whereas its memory could be overclocked by 1060 MHz.
Since the default clock rate of the Gigabyte card is somewhat lower than that of the above-discussed EVGA, the resulting frequency is lower, although the overclocking gain is the same.
When overclocked, the Gigabyte's GPU grew as hot as 75°C, the cooler's fans rotating at 2920 RPM.