NVIDIA GeForce 825M vs NVIDIA GeForce 830M vs NVIDIA GeForce 820M

NVIDIA GeForce 825M

The NVIDIA GeForce 825M  (sometimes also called GT 825M) is a middle class DirectX 12 graphics card. It is based on the 28 nm Kepler architecture and uses the same GK208 chip as the GeForce GT 730M and 740M.

Architecture

GK208 is based on the Kepler architecture and offers two shader blocks, called SMX, each with 192 shaders for a total of 384 shader cores. The shaders are clocked at the same speed as the rest of the chip. Furthermore, the GK208 chip has 16 TMUs and 8 ROPs on a 64-bit memory interface.

PCIe 3.0 is now supported by the mobile Kepler series and GPU Boost 2.0 mode can automatically overclock the card if the laptop cooling system allows it. This feature is available on any notebook with a graphics card from the 800M series.

Performance

According to our benchmarks, the performance of the GeForce 825M is somewhere between the GT 730M and GT 740M. Current games (as of 2013/2014) can thus be played in 1366 x 768 and medium settings. However, very demanding games such as Crysis 3 or Battlefield 4 will require lower resolutions and/or details.

Features

The feature set of the 825M corresponds to the GT 730M and 740M. This includes support for up to 4 active displays. Furthermore, high resolution monitors of up to 3840x2160 pixels can now 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) 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 feature is the inclusion of a dedicated video encoding engine similar to Intel QuickSync that can be accessed via the NVENCI API.

Power Consumption

The power consumption of the GeForce 825M should be similar to the GT 730M. As a result, the Nvidia GPU is best suited for multimedia notebooks 14-inches in size or greater. The 800M series also supports Optimus to automatically switch between an integrated graphics card and the Nvidia GPU.

NVIDIA GeForce 830M

The NVIDIA GeForce 830M is a (lower) mid-range, DirectX 12-compatible graphics card for laptops unveiled in March 2014. It is one of the first cards based on Nvidia's new Maxwell architecture (GM108 chip), but is still manufactured in 28 nm. The 830M offers 256 shader units clocked at 1029 MHz (+ Boost) as well as 2 GB of DDR3 memory (64 bit, 2000 MHz effective).

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. The 830M features a partially deactivated GM108 with just 2 out of 3 SMMs (256 shader cores, 16 TMUs, 8 ROPs, 64-bit interface). 

Another optimization is the massively enlarged L2 cache. The larger size can process some of the memory traffic to allow for a relatively narrow memory interface without significantly reducing performance.

Similar to GM107, the GM108 supports DirectX 12 (Feature Level 11_0 only).

Performance

According to Nvidia, the GeForce 830M is about 25 percent faster than the old GT 730M. Practically, the advantage is a bit smaller and the performance similiar to the old GeForce GT 740M (about 20 percent below the GeForce 840M). Many games of 2013/2014 will run fluently in WXGA resolution (1366 x 768) and medium detail settings. However, very demanding games such as Crysis 3 or Battlefield 4 will require even lower resolutions and/or details.

Features

GM108 integrates 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 830M should be about 25 Watts or less. Therefore, the 830M is best suited for laptops 13 inches in size or larger. The 800M series also supports Optimus to automatically switch between an integrated graphics card and the Nvidia GPU.

NVIDIA GeForce 820M