Intel HD Graphics 615 vs NVIDIA GeForce GTX 660 Ti vs Intel Iris Plus Graphics 640

Intel HD Graphics 615

The Intel HD Graphics 615 (GT2) is a low-end integrated graphics unit, which can be found in the Y-series of the Kaby Lake generation. This "GT2" version offers 24 Execution Units (EUs) clocked at up to 1050 MHz (depending on the CPU model). Due to its lack of dedicated graphics memory or eDRAM cache, the HD 615 has to access the main memory (2x 64bit DDR3L/LPDDR3).

Performance

The 3D performance of the HD 615 depends on the CPU model and the cooling / TDP-setting of the laptop. Furthermore, the used main memory (single channel, DDR3(L), amount) is influencing performance. On average the HD graphics 615 should be around 20 to 30 percent faster than the previous generation, the HD Graphics 615. Therefore, it may even reach the performance of the HD Graphics 520. Some low demanding games should therefore be playable with the chip.

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 m3-7Y30 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 HD Graphics 615 can be found in Y processors with 4.5 W TDP (can be manipulated by the laptop manufacturers) and is therefore suited for very thin, mostly passively cooled 2-in-1 notebooks and tablets.

NVIDIA GeForce GTX 660 Ti

The NVIDIA GeForce GTX 660 Ti is a high-end desktop graphics card based on the GK104 Kepler chip. It supports DirectX 11 and is manufactured in 28nm at TSMC. The core clock can be up to 980 MHz under load (GeForce Boost) and is a tleast 915 MHz. The GDDR5 VRAM is usually clocked at 1500 MHz (6000 MHz effective data rate).

Due to the higher core clock speed, the performance of the desktop GTX 660Ti is above the mobile GTX 680M (altough the 680M offers a wider memory bus of 256 Bit). Demanding games of 2013 should run in 1920x1080 with maximum settings and 4x Antialiasing fluently. Only Company of Heroes 2 and Hitman: Absolution scored below 30fps in our benchmarks on the average.

The chip offers the 5th generation video processor VP5, which is able to decode MPEG-1, 2, 4, H.264, VC1/WMV9 with a resolution of up to 4K. Furthermore, the included vidoe encoder called NVENC is able to encode H.264 vidoes without stressing the CPU.

The Geforce GTX 660Ti is rated at 150 Watt TDP and the default design uses two 6-pin power connectors.

Beware: For our benchmarks we used a slightly overclocked version that ran with 980-1059 MHz compared to the default 915 - 980 MHz. 

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.