NVIDIA GeForce GTX 880M SLI
The NVIDIA GeForce GTX 880M SLI is a high-end DirectX 12-compatible graphics card for laptops, consisting of two GeForce GTX 880M. Each card has a 28nm GK104 core based on the Kepler architecture. The clocks for the SLI-setup are usually identical to a single GTX 880M. With SLI, each card renders a single frame (AFR mode). Therefore, it may suffer from micro stuttering in low fps ranges of 30fps. This happens because of different timespans between two frames (e.g., irregular delays between sequential frames).
The Kepler architecture is the successor to the Fermi architecture that first appeared in laptops with the GeForce 400M series. The GK104 Kepler core offers eight shader blocks, called SMX, that are clocked at the same speed as the central core. In the GTX 880M, all eight blocks are active for a total of 1536 CUDA cores. Although the Kepler architecture can utilize more shader cores than a Fermi chip, its shaders can be up to twice as power efficient. However, due to the missing hot clock of the shader domain, two shaders of a Kepler chip are of similar speed to one shader of a Fermi chip (as the latter is clocked twice as fast).
The mobile Kepler series supports PCIe 3.0 as well as an optional Turbo mode, which can automatically overclock the card if the laptop cooling system allows it. This boost is supported by every GeForce 800M GPU.
Similar to our single GPU benchmarks, the GTX 880M SLI outperforms the GeForce GTX 780M SLI by about 10 percent. This makes the SLI configuration of two GTX 880M the currently fastest mobile graphics solution on the market (as of early 2014). With good driver support, SLI almost doubles the performance of a single card, allowing fluent frame rates even with FullHD resolution and highest detail settings.
The feature set includes support for up to 4 active displays. Furthermore, high resolution monitors of up to 3840x2160 pixels can be connected using DisplayPort 1.2 or HDMI 1.4a (if available). HD-Audio codecs, such as Dolby TrueHD and DTS-HD, can be transmitted via bitstream mode through the HDMI port. However, as most laptops will feature Optimus, the integrated GPU will likely have direct control over the display ports and may limit the feature set available by the Nvidia Kepler cards.
The 5th generation PureVideo HD video processor (VP5) is also integrated in the GK104 core and offers hardware decoding of HD videos. Common codecs such as MPEG-1/2, MPEG-4 ASP, H.264 and VC1/WMV9 are fully supported up to 4K resolutions while VC1 and MPEG-4 are supported up to 1080p. Two streams can be decoded in parallel for features such as Picture-in-Picture. Another novelty is the inclusion of a dedicated video encoding engine similar to Intel QuickSync that can be accessed by the NVENC API.
The power consumption of the GeForce GTX 880M SLI should double to at least 200 Watt (including board and memory) compared to a single GTX 880M. Therefore, only large desktop replacements can handle the heat.
|GeForce GTX 800M Series|
|Pipelines||3072 - unified|
|Core Speed||954 MHz|
|Memory Speed||5000 MHz|
|Memory Bus Width||2x 256 Bit|
|Max. Amount of Memory||2x 8192 MB|
|DirectX||DirectX 12 (FL 11_0), Shader 5.0|
|Transistor Count||2x 3540 Million|
|Features||Optimus, SLI, PhysX, Verde Drivers, CUDA, 3D Vision, 3DTV Play|
|Date of Announcement||12.03.2014|
|Link to Manufacturer Page||http://www.nvidia.de/object/geforce-gtx-...|