AMD Radeon 660M vs NVIDIA GeForce GTX 960M vs AMD Radeon 680M

AMD Radeon 660M

The AMD Radeon 660M is an integrated GPU in the entry level Ryzen 6000 series for laptops (Rembrandt, e.g. Ryzen 5 6600U). The GPU is based on the RDNA2 architecture and has 6 of the 12 CUs (= 384 shaders) clocked at up to 1,900 MHz (depending on the CPU model). The 680M and 660M iGPUs are the first integrated graphics card with hardware raytracing support, although the performance is too slow to use it in current games.

Due to the halved CU count and lower core clock, the Radeon 660M is clearly slower than the Radeon 680M and most likely only on par with the old Radeon Vega 8 iGPUs. 

Thanks to the modern 6nm 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 (depending on the CPU model).

NVIDIA GeForce GTX 960M

The NVIDIA GeForce GTX 960M is an upper mid-range, DirectX 11-compatible graphics card for laptops unveiled in March 2015. It is based on Nvidia's Maxwell architecture (GM107 chip) and manufactured in 28 nm. The GTX 960M offers 640 shader units clocked at 1097 - 1202 MHz (Boost) as well as fast GDDR5 memory (128 bit, 5000 MHz effective, 80 GB/s).

Compared to the previous and technically very similar GTX 860M, the GTX 960M is clocked 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. GM107 features 5 SMMs and thus 640 shader cores, 40 TMUs and 16 ROPs (128-bit interface).

Another optimization is the massively enlarged L2 cache (GM107: 2 MB). The increased size can handle some of the memory traffic to allow for a relatively narrow memory interface without significantly reducing the performance.

GM107 supports DirectX 12 with feature level 11_0 only.

Performance

Although the GTX 960M has the same memory bandwidth as the previous GTX 860M, its higher core clock leads to a slightly better performance. Overall, the 960M is almost 10 percent faster and similar to the desktop GTX 750 Ti.

Many games of 2014/2015 can be played fluently in FullHD resolution and high detail settings. However, very demanding games such as Assassin's Creed Unity will require lower resolutions and/or details.

Features

GM107 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 GTX 960M should be similar to the old GTX 860M (about 60 watts). Therefore, the GPU is best suited for 15-inch laptops or larger. The 900M series also supports Optimus to automatically switch between an integrated graphics card and the Nvidia GPU.

AMD Radeon 680M

The AMD Radeon 680M is an integrated GPU in the Ryzen 6000 series for laptops (Rembrandt, e.g. Ryzen 9 6980HX). The iGPU is based on the RDNA2 architecture and has 12 CUs (= 768 shaders) clocked at up to 2,400 MHz (depending on the CPU model). The 680M and 660M iGPUs are the first integrated graphics card with hardware raytracing support, although the performance is too slow to use it in current games.

Thanks to the new architecture, high core count and the increased maximum core clock, the Radeon 680M should be clearly faster then the old Radeon Vega 8 iGPUs. Therefore, the 680M should be the fastest integrated graphics card in early 2022. Compared to the dedicated Radeon 5300M (also RDNA), the 680M should still be significantly slower. According to AMD, the Radeon 680M (in the 6800U) is faster than a dedicated Nvidia GeForce MX450 and best suited for 1080p gaming and low details (for AAA games).

Thanks to the modern 6nm 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 (depending on the CPU model). The whole Ryzen 6000 chip can be configured down to 15W.