NVIDIA GeForce 940MX vs Intel UHD Graphics 620 vs NVIDIA GeForce 940M

NVIDIA GeForce 940MX

The Nvidia GeForce 940MX is a mid-range laptop graphics card with DirectX 12 support (FL 11_0). It has been announced in the first quarter of 2016 and is the refresh of the GeForce 940M. Compared to the older card, the new one is based on the same chip but now supports faster GDDR5. Therefore, it is similar to the Maxwell GPU in the Microsoft Surface Book but with more memory and higher clock speeds. However, most notebook vendors will use the slower DDR3 version of the 940MX that clocks only a few percent faster than the old GeForce 940M (1122 versus 1072 MHz base clock e.g.). 

For the GDDR5 version of the 940MX there appears to be also a variant with the GM107-B chip with 512 shaders instead of the 384 but lower clock speeds. The 940MX in the Acer Aspire E5-774G e.g. featured 512 shader cores (GM107) clocked at 795 - 861 MHz. The Dell Inspiron 17 7778 version however had the GM108 chip with 384 shaders clocked at 1083 - 1189 MHz.

The performance greatly depends on the used graphics memory and chip. According to our benchmarks (see below), the DDR3 version is very similar to the old 940M (due to only minor increased clock rates). The GDDR5 version however pushes ahead 20% (even 30% if paired with a fast desktop quad-core, but we lack 940M reference scores). Therefore, demanding games from 2015 should run fluently in low to medium settings and WXGA resolution. 

The TDP of the card should be rated at about 15 to 30 Watt (depending on the version, clock speeds and memory). Therefore, the GPU is best suited for laptops from 13-inch and up.

Intel UHD Graphics 620

The Intel UHD Graphics 620 (GT2) is an integrated graphics unit, which can be found in various ULV (Ultra Low Voltage) processors of the Kaby Lake Refresh generation (8th generation Core). Compared to the similar named Intel HD Graphics 620 in the 2016 Kaby Lake CPUs, only the name changed from HD to UHD. It is clocked with up to 1.150 MHz and therefore 100 MHz higher than the old HD Graphics 620 (max. 1.050 MHz) and offer a comparable performance. Due to its lack of dedicated graphics memory or eDRAM cache, the HD 620 has to access the main memory (2x 64bit DDR3/DDR4).

Performance

The exact performance of the UHD Graphics 620 depends on various factors like L3 cache size, memory configuration (DDR3/DDR4) and maximum clock rate of the specific model and as is similar to the Intel HD Graphics 620 and Intel HD Graphics 630. Compared to the average HD Graphics 620, the UHD graphics profits from the quad-core CPU a bit in our gaming benchmarks. Therefore, should be positioned between a GeForce 910M and 920M dedicated graphics card from Nvidia. For games, the drivers however are not that fast updated and tested as with GeForce graphics cards. In our tests, the UHD 620 is most suited for casual games like Team Fortress 2, Rocket League or Farming Simulator 17. See below for a list of modern games tested with various models.

Features

The revised video engine now supports H.265/HEVC Main10 profile in hardware with 10 bit colors. Furthermore, Googles VP9 codec can also be hardware decoded. The first models do not support HDCP 2.2 and therefore Netflix 4K. This was added with the new models in 2017 and beginning of May 2017 also the older CPU models like the i3-7100U are now shipped with a new S-Spec Code that supports HDCP 2.2. HDMI 2.0 however is still only supported with an external converter chip (LSPCon).

Power Consumption

The UHD Graphics 620 can be found in mobile processors specified at 15 W TDP and is therefore suited for compact laptops and ultrabooks. The power consumption during playing The Witcher 3 (with an external monitor) was comparable to a Intel HD Graphics 620 based laptop and on the lowest end of all of our measurements. Dedicated GPUs, like the GeForce 940MX, needed a lot more power.

NVIDIA GeForce 940M

The NVIDIA GeForce 940M is a mid-range DirectX 11-compatible graphics card for laptops unveiled in March 2015. It is based on Nvidia's Maxwell architecture (GM108 chip) and manufactured in 28 nm. The 940M offers 384 shader units as well as 2 GB of DDR3 memory (64 bit, 2000 MHz effective).

Compared to the previous and technically very similar GeForce 840M, the GeForce 940M is clocked just slightly higher.

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. GM108 features 3 SMMs and thus 384 shader cores, 24 TMUs and 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 Fermi and Kepler, the GM107/GM108 support DirectX 12 with feature level 11_0 only.

Performance

Due to its just 5 percent higher core clock, the GeForce 940M is only marginally faster than the previous GeForce 840M and similar to the older GeForce GT 750M (DDR3 version). Many games of 2014/2015 can be played fluently in WXGA resolution (1366 x 768) and medium detail settings. However, very demanding games such as Assassin's Creed Unity will require 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 940M should be about 30 Watts or lower. Therefore, the GPU is best suited for laptops 13 - 14 inches in size and above. The 900M series also supports Optimus to automatically switch between an integrated graphics card and the Nvidia GPU.