NVIDIA Quadro K620M vs Intel Iris Graphics 540

NVIDIA Quadro K620M

The Nvidia Quadro K620M is a DirectX 11 and OpenGL 4.5-compatible graphics card for mobile workstations. It is a Maxwell-based GPU built on the GM108 chip with 384 shader cores and manufactured in 28 nm by TSMC. The Quadro K620M is the successor to the significantly slower Quadro K610M. Usually, the GPU comes with 2 GB DDR3 memory clocked at 1000 MHz (2000 MHz effective, 16 GB/s). 

The Quadro series offers certified drivers that are optimized for stability and performance in professional applications like CAD or DCC. OpenGL performance, for example, should be significantly better than with GeForce graphics cards of similar specifications.

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% 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 reduce some of the memory traffic to allow for a relatively narrow memory interface without significantly hurting performance.

GM108 supports DirectX 11.2 (feature level 11.0 only) as well as DirectX 12.

Performance

Due to their identical specifications, the Quadro K620M offers a similar 3D gaming performance as the consumer GeForce 840M. Most games from 2014/2015 will run fluently in low or medium settings. Compared to other Quadro GPUs, the K620M performs almost similar to the older K1100M.

Features

The feature set should include support for up to 4 active displays. High-resolution monitors of up to 3840x2160 pixels can be connected using DisplayPort 1.2 or HDMI 1.4a (HDMI 2.0 not supported). 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.

Using CUDA or OpenCL, the cores of the Quadro K620M can be used for general calculations.

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).

Power Consumption

The power consumption of the Quadro K620M should be about 30 W including the board and memory components. Therefore, the GPU is best suited for laptops 13 - 14-inches in size and above. The K620M also supports Optimus to automatically switch between an integrated graphics card and the Nvidia GPU.

Intel Iris Graphics 540

The Intel Iris Graphics 540 (GT3e) is an integrated graphics unit of the Skylake generation. As successors of the HD Graphics 6000 (Broadwell), the Iris Graphics 540 can be found in CPUs of 15-watt series and offers 64 MB of dedicated eDRAM memory. Furthermore, the so-called GT3e-version features 48 Execution Units (EUs) clocked at up to 1050 MHz (depending on the CPU model). Besides the eDRAM cache, the Iris 540 is able to access the main memory (2x 64bit DDR3L-1600 / DDR4-2133).

Compared to the Iris Graphics 550 of the 28-watt series, the Iris Graphics 540 differs only by its slightly lower maximum clock and a nearly halved TDP, which limits the utilization of the Turbo Boost in certain situations.

Performance

The exact performance of the Iris Graphics 540 depends on various factors like memory configuration (DDR3/DDR4) and maximum clock rate of the specific model. The fastest versions (Core i7-6650U) should be slightly ahead of a dedicated GeForce 920M and will handle modern games (as of 2015) in low or medium settings.

Features

The revised video engine now decodes H.265/HEVC completely in hardware and thereby much more efficiently than before. Displays can be connected via DP 1.2 / eDP 1.3 (max. 3840 x 2160 @ 60 Hz), whereas HDMI is limited to the older version 1.4a (max. 3840 x 2160 @ 30 Hz). However, HDMI 2.0 can be added using a DisplayPort converter. Up to three displays can be controlled simultaneously.

Power Consumption

The Iris Graphics 540 can be found in mobile processors specified at 15 W TDP and is therefore suited for compact laptops and ultrabooks.