AMD Radeon RX Vega 8 (Ryzen 2000/3000) vs Intel Iris Plus Graphics 655 vs Intel Iris Plus Graphics 640

AMD Radeon RX Vega 8 (Ryzen 2000/3000)

The AMD Radeon RX Vega 8 is an integrated GPU for notebooks. It is used for the Ryzen 5 APUs, which were launched in the end of 2017. The GPU is based on the Vega architecture (5th generation GCN) and has 8 CUs (= 512 of the 704 shaders) clocked at up to 1100 MHz (Ryzen 5 2500U). The performance depends on the configured TDP (12-25 W at launch), the clocks, the cooling, and the memory configuration). The GPU should benefit from fast dual-channel DDR4-2400 RAM (contrary to DDR4-2133 single-channel, which is also possible).

The Vega architecture offers some improvements over the Polaris generation and now supports DirectX 12 Feature Level 12_1. More information is available in our dedicated article about the Raven Ridge architecture.

AMD's reference design GPU is sitting between the GeForce 940MX / Radeon Pro 450 and GeForce MX150 / Radeon Pro 555. It can handle smooth gameplay in simple titles like League of Legends (med), Dota 2 (low), Overwatch (low), CS:GO (med), and Quake Champions (high) in 720p up to 1080p according to AMD.

Thanks to the 14nm process and clever power-saving features, the power consumption is comparatively low (according to AMD), so the graphics card can also be used for slim and light notebooks.

Intel Iris Plus Graphics 655

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.