NVIDIA GeForce 845M
The NVIDIA GeForce 845M is a mid-range, DirectX 12-compatible graphics card for laptops unveiled in spring 2014. It is one of the first cards based on Nvidia's new Maxwell architecture, but is still manufactured in 28 nm. In addition to a version based on GM107 (partially deactivated to 384 ALUs, 128-bit, DDR3 memory), there is also another version using the GM108 chip (384 Shader, 64-bit, GDDR5 memory). Both models offer approximately the same performance.
Compared to Kepler, Maxwell has been optimized in several details to increase power efficiency. Smaller Streaming Multiprocessors (SMM) with only 128 ALUs (Kepler: 192) and an optimized scheduler should lead to better utilization of the shaders. Nvidia promises that a Maxwell SMM with 128 ALUs can offer 90 percent of the performance of a Kepler SMX with 192 ALUs.
Another optimization is the massively enlarged L2 cache (GM107: 2 MB). The larger size can process some of the memory traffic to allow for a relatively narrow memory interface without significantly reducing performance.
Similar to Fermi and Kepler, the GM107 and GM108 support DirectX 12 with feature level 11.0 only.
Thanks to the 128-bit memory interface (respectively the GDDR5 memory of the GM108 model), the GeForce 845M offers about 30 percent more performance than the GeForce 840M. However, a GeForce GTX 850M is still an additional 50 percent faster. Many games of 2013/2014 (Tomb Raider or BioShock Infinite, etc.) can be played fluently in 1366 x 768 and high detail settings. Very demanding games such as Crysis 3 or Battlefield 4 will require lower resolutions and/or details.
GM107/108 integrate the sixth generation of the PureVideo HD video engine (VP6), offering a better decoding performance for H.264 and MPEG-2 videos. Of course, VP6 supports all features of previous generations (4K support, PIP, video encoding via NVENC API). Unfortunately, HDMI 2.0 is still not supported.
The power consumption of the GeForce 845M should be in a range of about 30 - 35 Watts. Therefore, the card is best suited for 14-inch laptops or larger. The 800M series also supports Optimus to automatically switch between an integrated graphics card and the Nvidia GPU.
|GeForce 800M Series|
|Pipelines||384 - unified|
|Core Speed||1071 - 1150 (Boost) MHz|
|Memory Speed||2000 - 5000 MHz|
|Memory Bus Width||64/128 Bit|
|Max. Amount of Memory||2048 MB|
|DirectX||DirectX 12 (FL 11_0), Shader 5.0|
|Features||GPU Boost 2.0, Optimus, PhysX, CUDA, GeForce Experience|
|Notebook Size||medium sized|
|Date of Announcement||12.03.2014|