Geforce GTX 680 review

A new AA mode - TXAA

NVIDIA is to release yet another new AA mode that NVIDIA cooked up. TXAA is a new style anti aliasing technique that make the most of the graphics card high texture performance. TXAA is a mix of hardware anti-aliasing, custom CG style AA resolve and in the case of 2x TXAA an optional temporal components for better image quality. The new AA function will be available in two modes, TXAA 1 and TXAA 2.

• TXAA 1 should offer better than 8x MSAA visual quality with the performance hit of 2x MSAA.
• Then TXAA 2 offers even better image quality but with the performance of 4x MSAA

Unfortunately TXAA needs to be implemented in upcoming game titles, and this the functionality will be available later this year. TXAA will also get supported in GeForce series 400 and 500 products.

NVENC

NVENC a dedicated graphics encoder engine that incorporates a new hardware based H.264 video encoder inside the GPU. In the past this functionality was managed over the shader processor cores yet with the introduction of Kepler some extra core logic has been added dedicated to this function.

Nothing that new you might think but hardware 1080p encoding is now an option at 4 to 8x in real-time. The supported format here follows the traditional Blu-ray standard which is H.264 high profile 4.1 encoding as well as Multi-view video encoding for stereoscopic encoding. Actually up-to 4096x4096 encode is supported.

Above you can see Cyberlink Espresso with NVENC enabled and crunching our standard test. We tested and got some results

Now it's not that your processors can't handle this, but the big benefit of encoding over the GPU is saving watts and thus power consumption, big-time. Try to imagine the possibilities here with transcoding, video editing but also think in terms of videoconferencing and heck why not, wireless display technology.

Now above, you can find the results of this test. In this test we transcode a 200 MB AVCHD 1920x1080i media file to MP4 binary (YouTube format). This measurement is in seconds needed for the process, thus lower = better.

This quick chart is an indication as the different software revisions in-between the Espresso software and could differ a tiny bit. The same testing methodology and video files have been used of course. So where a Core i7 3960X takes 36 seconds to transcode the media file (raw over the processor) we can now have the same workload done in 12 seconds, as that was the result with NVENC. Very impressive, it's roughly twice as fast as a GTX 580 with CUDA transcoding and roughly a third faster then a Core i7 2600K with QuickSync enabled as hardware accelerator. The one thing we could not define however... was image quality. So further testing will need to show how we are doing quality wise.

And yes I kept an eye on it -- transcoding over the CPU resulted into a power draw of roughly 300 Watt for the entire PC, and just 190 Watt when run over the GeForce GTX 680 (entire PC measured). So NVENC not only saves heaps of time, it saves on power very much.