The watts for Raid and Sound cards PCI-E up to 4x should be keept @ 25watts . Thats all thas needed. For 8x 75watts - 200watts depending on Videocard. Most cards that pull 150watt plus under load will do best with 150-200watts. This will not hurt the Mobo ,it adds stability to allow the card to stay more stable under 100% load even @ stock or Overclocked.
Youll notice that when overclocking a videocard that the Higher lane watts allows the Card to achieve a higher Overall Overclock with out causeing the Driver to error.
Ive tested this with many cards and 3870/4870's @ 150- 200watts in the slot. Allows much higher OC on the Cards with better driver stability.
9800+/260/280/ and so forth like arond 150watts any Nvidia Dual GPU card 200watts will do.
When not overclocking or pushing the HTT/Southbridge 75watts is fine for the 8x and 16x slots. I have found that even with my 3870x2 that @ 75watts it maxes @ 880mhz both cores . When i run 150+Lane watts for the 16x lane I can Clock 945mhz both cores. The chip set and mobo seem to like this with power hungry cards.
If i was gonna hurt anything ,, would of toasted this M3A79-T long ago.
Trust me ive pushed every limit possiable :D