Upgrade PSU or not

[Edward95]

Last Christmas I bought a new PC. The spec are
PCPartPicker part list: http://pcpartpicker.com/p/vQdMgs
Price breakdown by merchant: http://pcpartpicker.com/p/vQdMgs/by_merchant/

CPU: Intel Xeon E3-1231 V3 3.4GHz Quad-Core Processor ($241.99 @ SuperBiiz)
Motherboard: ASRock Fatal1ty Z97X Killer ATX LGA1150 Motherboard ($121.98 @ Newegg)
Memory: Corsair Vengeance 16GB (2 x 8GB) DDR3-1600 Memory ($119.99 @ Amazon)
Storage: Crucial MX100 256GB 2.5" Solid State Drive ($108.99 @ SuperBiiz)
Storage: Western Digital BLACK SERIES 2TB 3.5" 7200RPM Internal Hard Drive ($124.99 @ Amazon)
Power Supply: XFX 550W 80+ Bronze Certified ATX Power Supply ($45.99 @ NCIX US)
Total: $763.93
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-03-27 01:55 EDT-0400

I have planned to get a GTX 970 but unfortunately, my monitor broke so I have to take the money and get new want leaving me with an gainward GTX 750 Ti GS 'cause I am out of budget.

Last week I went out and bought an Gigabyte G1 Gaming GTX 970 but yesterday I receive an MSI GTX 970 gaming 4G from my brother who did not know i already have an 970.

On Pcpartpicker it said that my 2 970s in sli is compatible with 550 w PSU but i only have 50w to spare. Do I need to go and pick up a new PSU asap?

 

[ParadoxInfinite]

I think it would be a good idea to upgrade your PSU. I think something around 700W should be fine. I wouldn't completely rely on the PCPartPicker's power consomption calculator. If I were you, I would buy a new PSU.

 

[Xrunner98]

http://pcpartpicker.com/part/evga-power-supply-220g20750xr

The 750 G2 is a really great choice because it is 80+ Gold and it has "eco mode" which lets you turn the fan off to reduce noise level. For what it offers, it is not expensive and if you run 2 970s I would buy this psu. And don't think that you will have 50 W to spare because PSUs are a lot more complicated than that. You have to take into consideration the quality of the caps and the 80+ rating.