The first benchmarks of the Steam Deck handheld console in several AAA and eSports games have been published by a Chinese user. The performance was benchmarked on a development kit that more or less matches the specifications of the final variant however performance may improve in the final retail variant.
Source: N4G PC Steam Deck Benchmarked- 60 FPS In Several AAA Games, 30 FPS in Cyberpunk 2077