The power supply of Lenovo brand machine is very low, so you should use a rated 230W power supply for this machine.
So if you want to install a discrete graphics card on your Lenovo computer, you can only consider those graphics cards that consume less than 75W.
For example: GTX650, GTX750, HD6670, HD7750, R7 250, the graphics card with the strongest comprehensive performance is GTX750, but the price is not cheap.
Graphics performance from strong to weak:
Zhong Ying GTX750 NetGod Edition, memory 1G, GTX750 new edition, power consumption of 55W, RMB 849.
Galaxy GTX750 Black General, memory 1G, new GTX750, power consumption 60W, RMB 849.
Gigabit GV-N750OC- 1GI, video memory 1G, new GTX750, power consumption 60W, RMB 899.
Inch GTX650 Tiger General, memory 1G, GTX650 version, power consumption 60W, ￥675.
Zhong Ying GTX650 game God of War version, memory 1G, GTX650 version, power consumption 65W, RMB 699.
Galaxy GTX650 Black General, memory 1G, GTX650 version, power consumption 65W, RMB 749.
Gigabit GV-N650OC- 1GI, video memory 1G, GTX650 version, power consumption of 65W, RMB 749.
Xuan Ming R7 250 transformer, 1G memory, AMD R7 250 new version, power consumption of 75W, ￥549.
Onda R7 250 Aegis 1GD5, memory 1G, AMD R7 250 new version, power consumption 75W, RMB 549.
His H250q 1Geiceq, video memory1g, AMD R7 250 new version, power consumption 75W, RMB 599.
MSI R7 250 1GD5/OC, video memory 1G, AMD R7 250 new version, power consumption 75W, RMB 599.