In short — Alienware m15 R7 15.6" QHD 240Hz outperforms the cheaper Acer Nitro 5 AN515-45 15.6 Inch on the selected game parameters. However, the worse performing Acer Nitro 5 AN515-45 15.6 Inch is a better bang for your buck. The better performing Alienware m15 R7 15.6" QHD 240Hz is 142 days older than the cheaper Acer Nitro 5 AN515-45 15.6 Inch.