DellUser1 is correct. Similar features does not mean similar quality.
I took a look at the two web pages you provided. Important technical information is missing on both of those pages.
A high quality 500-550 watt power supply can easily power any single video card made. You do not need a 650 watt power supply for a HD 4800 series video card. Here is a link to a technical review of the Corsair VX550 power supply which comes with two PCIe 6 pin video power cables:
which Watts should I get, just for overclocked ATI 4890 and overclocked newer graphic card with higher wattage use like 650W or higher. I only reply on single card since crossfire aren't supportable for all-around use.
which Watts should I get, just for overclocked ATI 4890 and overclocked newer graphic card with higher wattage use like 650W or higher. I only reply on single card since crossfire aren't supportable for all-around use.
As mentioned by JohnnyLucky, the Corsair VX550 is plenty of power. There is no single GPU that uses over 200W, and most are less than 150W.