Is worth buying Sapphire r7 250x 1gb GDDR5 or Asus R7 250x 1gb ddr5 ??

Solution
250 does not require, but 250X requires additional power connector. Regardless of this, the cards do not use much power - almost any 400-450W PSU will do. If the PSU is from a known brand - better.
The cards are good if they fir your budget. The Asus will be a little faster (it's factory overclocked)

amtseung

Distinguished
The R7-250 itself doesn't require any external 6-pin connectors, so unless you plan on overclocking it to pluto and back with liquid nitrogen, I'd think a 450-500W power supply is plentiful. (Antec VP450. Do it. It's rated at 450W, but pushes 550W no problem with little to no extra heat produced. Unless SLI/XFire, then...)
As for which brand, I'd always say pick the cheaper one, but the brand war will rage on forever. Some swear by Sapphire, others swear by Asus. I just get whatever works best for the least money. My poor little Asus r7-240 (2gb ddr3) was overclocked to all hell and beyond, (1017mhz core, 1325mhz mem) and it was more stable than I ever thought it would be.
 
250 does not require, but 250X requires additional power connector. Regardless of this, the cards do not use much power - almost any 400-450W PSU will do. If the PSU is from a known brand - better.
The cards are good if they fir your budget. The Asus will be a little faster (it's factory overclocked)
 
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