I don't know for sure but if it doesn't use a PCIe connector from the PSU then it runs in 75watts or less. If it does use a connector from the PSU and your research says around 110 watts give it some margin and think of 150watts just to be safe
I have an XFX Radeon HD 4770 currently in my system, with an older 535 watt Enermax PSU with 4 GB's of DDR2 800Mhz ram and have played the Call of Duty games (COD4,Modern Warfare 2 and 3 and even Battlefield 2 at medium settings)) without any problems. But before I purchased the Enermax, I ran the card and games with a generic 500watt PS and they still ran OK. So you should be fine. Only a 6-pin power connector is required and I believe your power supply has one. Yes, some sites do say that it's an 80 watt at idle card, but even at a higher wattage, it will be no problem. Hope this helps.