04-20-2017 10:28 PM
04-21-2017 04:20 AM
Yes you can replace the power supply with 400 W power supply. Make sure it has 6-pin power connector for the card if it needs one (not all 750ti need the extra power).
In fact if you use the original GTX 750ti produced by Nvidia you do not even need to change the PSU as there will be enough power to power the Graphic card:
Only if you choose to buy a gtx 750ti from different manufacturer (overclocked) with the need for 6-pin power connector I would recommend to change the power supply.
Hope it helps,