Upgrading my PC

[LameElite]

I have GTX 950 and my i3 540 doesn't perform really good with it. I want to buy new CPU. I have 400 USD. Could you tell me what should I buy? I have 400 W PSU.
I will play some games on it and make 1080p videos. It cannot be used

 

[theonerm2]

PCPartPicker part list: https://pcpartpicker.com/list/dwQ3WX
Price breakdown by merchant: https://pcpartpicker.com/list/dwQ3WX/by_merchant/

CPU: Intel - Core i5-7400 3.0GHz Quad-Core Processor ($176.44 @ OutletPC)
Motherboard: ASRock - B250M-HDV Micro ATX LGA1151 Motherboard ($62.99 @ SuperBiiz)
Memory: Team - Dark 16GB (2 x 8GB) DDR4-2400 Memory ($94.99 @ Newegg)
Total: $334.42
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2017-05-13 12:40 EDT-0400

 

[Finstar]

I have GTX 950 and my i3 540 doesn't perform really good with it. I want to buy new CPU. I have 400 USD. Could you tell me what should I buy? I have 400 W PSU.
I will play some games on it and make 1080p videos. It cannot be used

PCPartPicker part list / Price breakdown by merchant

CPU: AMD - Ryzen 5 1500X 3.5GHz Quad-Core Processor ($188.98 @ NCIX US)
Motherboard: ASRock - AB350M Pro4 Micro ATX AM4 Motherboard ($84.99 @ SuperBiiz)
Memory: Corsair - Vengeance LPX 16GB (2 x 8GB) DDR4-3000 Memory ($126.94 @ Amazon)
Total: $400.91

 

[atljsf]

i would buy a psu too, becuse we don't know whicch one is and how good quality is, also 400 watts sounds like it doesn't have the right modern connectors needed for the upgrade that most people usually do, good mainboard, good gpu