Video output is set for 120 Hz to reduce latency. Compared to the standard Xbox One S, power consumption has been reduced by 30% through processor-specific power tuning. Each server initially had four customized Xbox One S-based units for the 2018 teaser, but this was doubled to eight per server in a 2U enclosure for the service's launch in 2019. The hardware at launch used Xbox One S-based blade servers, but began to transition to Xbox Series X-based servers in June 2021. Microsoft said that its Xbox content library will make its service more appealing than competitors such as Stadia. It entered public testing later in the year and was unveiled at E3 2019. The service entered its home testing phase in May 2019, when it could be used outside the lab environment. Xbox head Phil Spencer used a private server during this time to test games on a remote connection. They demonstrated the service in March 2019 with the racing game Forza Horizon 4 playing on an Android smartphone with an Xbox One controller. Microsoft teased the service at E3 2018 and formally announced Project xCloud several months later, in October 2018.