Cooler Master Quick Fire Rapid (Black Switch) Question

[polod]

guys just got my new gaming mechanical keyboard today the Cooler Master Quick Fire Rapid (Black Switch), and i would like to ask on which to plug? USB or PS/2 mode?
got this keyboard exactly for gaming and no typing thats why i choose black, red is not available, and i don't know regarding the N Key Roll Over thing or what the hell that means?hehehe would i benefit from it in gaming?
so thats it thanks in advance for your answers..

 

[popatim]

ps/2 polling rate is 10k minimum and 16k maximum.
usb polling rale it 125 no I didnt forget the k, just plain old 125
usb can transmit 500 keystroke at once if you could type that many in 8ms. LOL

Most gaming mice let you change the usb polling rate. perhaps this keybd can also. Check the owners manual.