Radeon ReLive
The Radeon ReLive is not only especially designed for AMD GPUs, but also is free to use.
This one too, uses the GPU for the encoding of the video, reducing the impact on CPU performance. One of the best features of this software is that it allows upscalling of resolution. It means that you don’t necessarily need a 4k display to record in 4k resolution – 1080p would do too.
It comes with limited features and is compatible only with AMD GPUs. However, it is quite simple to learn and use.
Compatible with: RX Vega, 500 Series Graphics products; Radeon R9 Fury, Radeon Pro Duo, and Radeon RX 400 Series; AMD Radeon R9 200, R7 200, R5 300, R5 240 Series; AMD Radeon™ HD 8500 – HD 8900 Series; AMD Radeon™ HD 7700 – HD 7900 Series.