WPC how to read?

I have NAD T753. My speakers are 4ohm. My receivers specs read,

Power Output Stereo Mode 2 x 90W (19.5dBW)
IHF Dynamic Power 8 Ohms 2 x 150W (21.7dBW)
IHF Dynamic Power 4 Ohms 2 x 200W (23dBW)
IHF Dynamic Power 2 Ohms 2 x 225W (23.5dBW)

Is it accurate to say my speakers are receiving 200WPC?
Or am I getting only 90W?

In stereo mode your speakers will be getting 90 watts RMS (continuous). In surround mode your speakers will be getting 70 watts RMS. NAD amps are unique in that they put the same amount of continous power into an 8 or a 4 ohm load. IHF power refers to peak (dynamic) power output. That's power measured in millisecond bursts. While it's good to know that the amp has that kind of headroom (especially for audio peaks and transients), it's not something you use to measure absolute power.

http://www.nadelectronics.com/av_rec...3_frameset.htm

It's a fairly safe bet that 95% of the time your receiver isn't even outputting more than 5-10 watts per channel, and for that 5% of the time it does, rest assured that there's plenty of juice left to handle the dynamic peaks.
Me thinks you picked a good receiver there for them speakers....

Thanks for the help.

One more question though,

Since my mains are rated as such,
Impedance 4ohms
Frequency response 33Hz - 32Hz
Sensitivity 87 db
Power range 110-180 W.
Crossover frequency 33Hz -32Hz.

Is my A/V Receiver sufficient enough to handle these speakers?
Or, would you recomend i use my Rotel 2 ch amp for my mains (RB-870BX 100wpc)?

One would have to define "sufficient." In my mind, this means amplifying the sound loud enough without distortion and without overheating the receiver. The only way to confirm or deny this would be to actually test it in your room with your speakers. Sure, an external power amp will free up some power for the receiver, but you should first find out if it is necessary.

I would go with an external amp as a last resort, because the voicing may sound different across the surround channels. I would also consider amplifying all channels with an external multi-channel amp.

First off, your amp is rated at "up to" 90 watts per channel into an 8 ohm resistor. There are times it will put out more than that into a speaker, sometimes less. Not that it really matters that much.

The bulk of your listening is done at less than 1 watt. You may hit occasional dynamic peaks of 5 watts, maybe a bit more, but not usually much more even if you've got some really dynamic music. That is pretty loud.

Be concerned with the quality of the amplifier rather than the quantity. I would rather have a 50 watt amp that is done right, than a 200 watt amp that is done wrong. The dynamic numbers listed are peak instantaneous figures into a dummy load, and are good for a couple of milliseconds, not continuous...if you are still interested.