Graphics Card Design and Features
The new GeForce GTX 780 looks like a copy of the GeForce GTX Titan except for the text on the cooler casing and the lack of memory chips on the reverse side of the PCB.
You may be pleased to know that the GeForce GTX 780 has the same highlighting on its top edge as the Titan:
The new graphics card is equipped with three video outputs: dual-link DVI-I and DVI-D, HDMI 1.4a and DisplayPort 1.2.
Thus, you can connect as many monitors to the GTX 780 simultaneously as to the Titan. There are no differences in terms of the power and SLI connectors:
The PCB of early samples of the GeForce GTX 780 card is an exact copy of the Titan’s PCB.
Except for the mentioned changes on the reverse side of the PCB, everything is identical. The GPU voltage regulator includes six phases based on DrMOS transistors, and there are three more phases for the memory chips and PLL.
Like on the Titan, the power system is managed by an NCP4206 controller from ON Semiconductor.
It is possible that off-the-shelf GeForce GTX 780s will have a different PCB, though.
The GPU of our sample was manufactured in Taiwan on the 36th week of 2012. So, Nvidia had working GK110 chips as far back as the early September of the last year.
The GPU die is 561 sq. mm large and marked as GK110-300-A1 (the Titan die is marked as GK-110-400-A1). Just as officially specified, the GPU is clocked at 867/902 MHz in 3D applications at a voltage of 1.162 volts. The clock rate is dropped to 324 MHz in 2D applications and the voltage is lowered to 0.875 volts.
On the face side of the PCB, under thermal pads, there are 12 FCBGA-packaged chips of GDDR5 memory for a total capacity of 3 gigabytes. These Samsung Semiconductor chips are marked as K4G20325FD-FC03:
In 3D mode the GeForce GTX 780 has a memory frequency of 6008 MHz. Coupled with the 384-bit bus, this yields a peak bandwidth of 288.4 GB/s, just as with the Titan.
The latest version of the GPU-Z utility is already familiar with the GeForce GTX 780:
The cooling system is a copy of the Titan's, too. It has a vapor chamber in its base, an aluminum heatsink, a metallic frame and a radial fan with optimized rotation speed.
The hot air from the cooler is exhausted out of the computer case.
The GeForce GTX 780 features a new adaptive fan regulation algorithm, so the fan changes its speed smoothly under 3D loads.
To check out the card’s temperature we used five runs of the Aliens vs. Predator (2010) benchmark at the highest visual quality settings, at a resolution of 2560x1440 pixels, and with 16x anisotropic filtering and 4x MSAA.
We used MSI Afterburner 3.0.0 beta 10 and GPU-Z version 0.7.1 for monitoring of temperatures inside the closed system case, which configuration is discussed in detail in the following chapter of the review. All tests were performed at 25°C room temperature.
With the cooler’s fan regulated automatically, the GPU quickly got as hot as 82°C and stayed like that for the duration of our test. The fan accelerated to 2350 RPM to prevent a further temperature rise.
Auto fan mode
Max fan speed
When the radial fan was rotating at its maximum 4270 RPM, the GPU was only 57°C hot. We can also note that the peak GPU clock rate was 1006 rather than 902 MHz during our tests (the Power and Temp Targets had been set at their maximums). That’s GPU Boost 2.0 for you.
The noise level of each cooler was measured between 1:00 and 3:00 AM in a closed room about 20 m2 big using CENTER-321 electronic noise meter. The noise level for each cooler was tested outside the system case when the only noise sources in the lab were the cooler and its fan. The noise meter was installed on a tripod and was always at a 150 mm distance from the cooler fan rotor. The tested cooling systems were placed at the edge of the desk on a sheet of polyurethane foam. The lowest noise reading our noise meter device can register is 29.8 dBA and the subjectively comfortable noise level in these testing conditions was around 36 dBA (do not mix it up with low noise level). The fan(s) rotation speed was adjusted in the entire supported range using our in-house controller by changing the voltage with 0.5 V increment.
The noise level of the Nvidia GeForce GTX 780 is compared in the diagram with that of the reference AMD Radeon HD 7970 GHz Edition:
Indeed, Nvidia’s card is quieter throughout the entire speed range. Even at the maximum speed of its fan, the GeForce GTX 780 is not as loud as the Radeon HD 7970 GHz Edition. On the other hand, the new card can't be called really quiet in 3D applications. 3-5 minutes into a benchmark or 3D game, the sound of the GTX 780's cooler would rise above the background noise of our computer. At the speed of 2350 RPM we’ve seen above in the temperature tests the noise level was too high for the card to be called comfortable. It is only in 2D mode that the GeForce GTX 780 would quiet down and get lost among the other computer noises. Hopefully, the original GeForce GTX 780 cards with alternative coolers that have been already announced aplenty will be both cool and quiet.