The GeForce GTX 680 was Nvidia's first 28 nm part with 1536 CUDA cores, 128 texture units and 32 ROP units. It has remained since the release of the fastest single-GPU graphics card in the Nvidia series, which ranks second after the GTX 690 with two GPUs and two GK104 GPUs.
And so the GTX 680 and the Radeon HD 7970 have fought for the top performance in the last more than 12 months and forced numerous price reductions and even a little overclocking from AMD to produce the 7970 GHz Edition. In the end, AMD was able to undercut Nvidia's price and produce what we think is the better solution.
Most recently, however, Nvidia showed what they could really do with the GK104 architecture by spicing it up with more CUDA cores, texture units, and ROPs to create the GK110. The GeForce GTX Titan is a monster that belongs to a completely different league and destroys the GeForce GTX 680 and the Radeon HD 7970 GHz in every possible way. In real game tests, the GTX Titan outperformed the GTX 680 by 42% and the Radeon HD 7970 GHz Edition by 30%. In the past, we've seen performance leaps of 20-25% from one generation to the next, so these numbers are indeed special.
But of course, apples and oranges are compared with a price tag of $ 1,000. If anything, the Titan showed how much more complex and powerful Nvidia can make the current generation 28nm GPU without surpassing the TDP rating. It also meant Nvidia could move to the mainstream next-generation GPUs without having to completely redesign their architecture for the GeForce 700 series, which is exactly what they did.
The new GeForce GTX 780 is based on a similar, albeit slightly scaled-down, version of the Titan GPU that manages to retain many of the features that make the $ 1,000 graphics card great, such as the 384-bit memory bus.
GeForce GTX 780 in detail
The GeForce GTX 780 reference board is 26.7 cm long. The display outputs include two dual-link DVIs, an HDMI and a DisplayPort connection. With 2304 CUDA cores, the GeForce GTX 780 has 50% more CUDA cores than the GeForce GTX 680. The GTX 780 also has a 3 GB memory buffer standard that is 50% higher than that of the GTX 680.
To use the additional memory, six 64-bit memory controllers help for a 384-bit wide memory bus. In conjunction with a 6008 MHz GDDR5 memory clock, the GPU offers up to 288.4 GB / s maximum memory bandwidth.
These specs mean that those who still rock a GeForce GTX 580 should expect a performance improvement of around 70% when upgrading to the GTX 780. Not only GTX 580 owners can expect a decent increase in performance, as owners of last year's GTX 680 will continue to get around 30-40% more power, at least on paper.
The 12 SMX units with 2304 CUDA cores are clocked at 863 MHz, although they can be clocked up to 900 MHz with Boost 2.0 in certain scenarios. The second generation GPU Boost technology works in the background and dynamically adjusts the graphics clock rate of the GPU to the operating conditions.
Originally, GPU Boost was developed to bring the GPU to the highest possible clock rate while staying within a predefined performance envelope. However, Nvidia engineers found that GPU temperature is usually the first to limit performance. So with Boost 2.0, they changed how the technology works, increasing clock speeds based on the GPU temperature rather than the performance goal. The new target in question for the GTX 780 is 80 degrees Celsius.
In other words, the GTX 780 will automatically increase to the highest clock speed it can reach as long as the GPU temperature stays at 80 ° C. Boost 2.0 constantly monitors the GPU temperature and adjusts the GPU's clock rate and voltage during operation in order to maintain this temperature.
Nvidia borrowed the design of the GTX Titan for the GTX 780, which is good news as the Titan not only looked imposing but was also whisper-quiet. Many other newer high-end GPUs like the GTX 780 use vapor chamber cooling, which consists of a copper vapor chamber that extracts heat from the processor using an evaporation process similar to a heat pipe but more powerful. A new thermal material developed by a company called Shin-Etsu, which is said to offer twice the performance of the grease used in the GTX 680, helps improve efficiency.
In addition, Nvidia has installed an additional heat sink behind the 80 mm fan, which increases the cooling area. There is also an aluminum base plate that provides additional cooling for the circuit board and board components. The guts of the cooling process are covered in a case that encloses the top of the card.
Given the high-end nature of this board, Nvidia's engineers decided to use an aluminum case for the cover. In the center is a clear polycarbonate window that allows you to see the vapor chamber and heat sink with two slits that are used to cool the GPU.
Another nice touch in our opinion: There is a large GeForce GTX logo on the side of the card that glows green when the system is turned on. We think that's cool, but if it isn't for you, the LED intensity can be adjusted in the software.
There are two PCI Express power connectors next to the logo at the end of the card. The configuration is the same as the GTX Titan, meaning you will find a single 8-pin and a 6-pin connector. The GTX 780 has a TDP of 250 watts, which is 28% more than the GTX 680. Nvidia therefore recommends using a 600 W power supply. The board has a 6 + 2 power phase design which, according to Nvidia, provides enough power even when overclocking. Six phases are assigned to the GPU, two phases to the GDDR5 memory.