High-speed G-series trains on the Shanghai to Jianxi corridor run on the Shanghai–Kunming High-Speed Railway, linking Shanghai Hongqiao with key Jiangxi gateways such as Nanchang West and Shangrao. These trains offer Second Class, First Class, and Business Class seating, with operating speeds of 300–350 km/h (186–217 mph) depending on the section. The fastest G-series services reach Nanchang West in about 3 hours 40 minutes to 4 hours, typically calling at major stations like Hangzhou East, Jinhua, and Shangrao, while Shanghai to Shangrao takes roughly 2 hours 10 minutes to 2 hours 40 minutes. By contrast, classic T/K overnight trains from central Shanghai Station to cities in Jiangxi (e.g., Nanchang, Jiujiang) run at 120–140 km/h (75–87 mph) and take around 9 to 12 hours, with many intermediate stops. Onboard, G-series trains provide assigned seating, power outlets, and trolley service, making them the fastest option. Traditional T/K trains offer hard/soft seat and sleeper berths for overnight travel. Choose G-series for the shortest daytime journey, or opt for an overnight T/K if you prefer to travel while you sleep.