The NVIDIA GeForce 820M (or GT 820M) is an entry-level DirectX 12 compatible graphics card announced in January 2014. Its core is based on the 28nm GF117 chip (Fermi architecture) and is equipped with 64-bit DDR3 memory. Besides the slightly different clock rate, the 820M is almost identical to the old GeForce 710M and GT 720M.
Architecture
The GF117 is based on the optimized GF108 Fermi chip (GeForce GT 540M) and offers 96 shaders, 16 TMUs and 4 ROPs. Each shader core is clocked twice as fast as the rest of the graphics chip, a technique known as hot clocking. More detailed information on Fermi can be found on the GT 435M GPU page.
It should be noted that the GF117 does not offer dedicated graphic ports and can therefore only be used in conjunction with Optimus.
The 820M supports GPU Boost 2.0, which can automatically overclock the card if the laptop cooling system allows it. This feature is available on any notebook with a graphics card of the 800M series.
Performance
In our gaming benchmarks, the 3D performance of the GeForce 820M is similar to the former GT 720M and the Intel Iris Graphics 5100. This places the card in the entry level segment. Current games (as of 2013/2014) will run fluently only in low settings and resolutions.
Features
The shader cores (also called CUDA cores) can be used for general calculations with APIs such as CUDA, DirectCompute 2.1 and OpenCL. PhysX is theoretically possible, but the 820M is too slow to handle both PhysX and 3D rendering in modern games. 3D Vision is not supported according to Nvidia.
Power consumption
The power consumption of the Geforce 820M should be similar to the old GT 720M. As a result, the GPU is best suited for notebooks 13 inches in size or greater.
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.
Architecture
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.
Performance
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.
Features
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.
Power Consumption
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.
- Range of benchmark values for this graphics card - Average benchmark values for this graphics card * Smaller numbers mean a higher performance 1 This benchmark is not used for the average calculation
Game Benchmarks
The following benchmarks stem from our benchmarks of review laptops. The performance depends on the used graphics memory, clock rate, processor, system settings, drivers, and operating systems. So the results don't have to be representative for all laptops with this GPU. For detailed information on the benchmark results, click on the fps number.