AMD Radeon HD 8400 vs Intel Iris Plus Graphics 640

AMD Radeon HD 8400

The AMD Radeon HD 8400 is an integrated DirectX 11.1 graphics card typically paired with AMD Kabini-class APUs (for example, the A6-5200). It has 128 shader cores and two Compute Units based on the GCN architecture and is clocked at 600 MHz with no support for Turbo. The GPU does not have dedicated VRAM and will access the main memory of the system (up to single-channel DDR3L-1600).

The HD 8400 integrates both UVD 4.2 and VCE 2.0 video encoders. It supports up to two external monitors via VGA, DVI, HDMI 1.4a and DisplayPort 1.2.

Depending on the benchmark, the performance of the Radeon HD 8400 is similar to some faster Intel HD Graphics 4000 models. This is on par with a dedicated Radeon HD 6490M, but is still too slow for a number of demanding games as of 2013/2014. However, many older and less demanding games will run fluently if the performance of the CPU is sufficient.

Intel Iris Plus Graphics 640

The Intel Iris Plus Graphics 640 (GT3e) is a processor graphics card for Kaby Lake models announced in January 2017. As the successor to the Intel Iris Graphics 540 (Skylake), the Iris Plus Graphics 640 is used for 15-Watt ULV models and is equipped with 64 MB eDRAM cache. There should not be any big changes compared to the Iris Graphics 540.

The so called GT3e version of the Kaby Lake GPU still has 48 Execution Units (EUs), which can reach up to 1050 MHz depending on the model. Besides eDRAM cache, the Iris 640 can also access the system memory (2x 64 Bit DDR3L-1600/LPDDR3-1866/DDR4-2400) via processor interface.

Compared to the Iris Plus 650 from the 28-Watt models, the Iris 640 only has a slightly lower maximum clock as well as the lower TDP, so the utilization of the Turbo Boost potential should be worse.

Performance

The exact performance of the Iris Plus Graphics 640 depends on the CPU model, because maximum clock as well as the size of the L3 cache can differ a bit. The system memory (DDR3/DDR4) will influence the performance as well.

The fastest chips are high-clocked Core i7 models like the Core i7-7660U. Depending on the game, the Iris Plus 640 will probably be similar to the previous model somewhere between a dedicated GeForce 920M and GeForce 940M and is usually limited to low settings in modern games.

Features

The reworked video engine now fully supports hardware decoding of H.265/HEVC videos. Contrary to Skylake, however, Kaby Lake can now also decode H.265/HEVC Main 10 with a 10-bit color depth as well as Google's VP9 codec. The video output is possible via DP 1.2/eDP 1.3 (up to 3840 x 2160 @60 Hz), whereas HDMI is also supported in the older 1.4a standard. An HDMI 2.0 output can be added via converter from DisplayPort. The GPU can drive up to three displays simultaneously.

Power Consumption

The Iris Plus Graphics 640 is used for 15-Watt ULV processor and therefore thin notebooks and Ultrabooks.