I'm about tp purchase the Acer X34 (3440x1440, 100 Hz) and wanted the hardware to support it. The GTX 1080 just came out and it's for around 650$ (aftermarket coolers). The 980 Ti on the other hand is for 500$ right now on Amazon and looks like a great deal. Should I buy one GTX 1080 or two 980 Ti's?