If the label were accurate, yes. Unfortunately, that Coolermaster series is overrated and otherwise low quality, so I wouldn't. A quality PSU has full range active PFC (no little voltage switch; unlike that CM), and 80+ certification. Antec, Seasonic, Corsair, Enermax, and XFX are among the better brands. Although inefficient, that CM PSU will suffice for a single card, but when you get the second, I'd replace the PSU also, probably with a 650W Antec Truepower New or Seasonic X-650.
With a 125W Cpu and crossfired 5770's, you may be looking for problems down the line with that model PSU. Although it meets the recommended minimum wattage for 5770's in crossfire (600W), it is not a strong unit. Not to knock CM products (I have a Silent Pro 600 for 5770's x-fired), yours is a lower end product that is going to power higher end components.