Mobo Asus A8N32-SLI Delux: What are NB & SB ?

[vv_boy]

I just finished building my first computer. The spec. are as indicated below. I got everything working. However, I notice that on the Mobo there are fan plugs for NB and SB. What are these fan plugs for? Do I need to get fands for them? If so, where would I place the fans?
I also got an optional fan came with the Mobo. But the Mobo indicates that this fan can only be used with a passive cooling, eg water cooling. Is water cooling better than air cooling.
More over, my CPU temp. sometime gets up to 57C. Should I worry about this high temp.? I am current using three chasis fans: front, rear and top. Your opion on this matter is very much appreciated.

Thanks,

 

[Sophocles]

I don't own the board but I believe that NB and SB stand for North bridge and south Bridge. The A8N32-Sli conatins both North and south bridge chipsets to accomodate two 16 bit PCIe cards, versus the A8N-SLI Deluxe and premium which have only a south bridge chipset which allows for two card 16 bit graphics cards but only at 8 bits each. I would have to see the layout of your board to determine why there would be connections for chpset fans on a passively cooled board but I can understand why. I own both the A8N-SLI deluxe and Premium boads. The premium uses passive cooling and the Deluxe uses a heat sink fan combo. I replaced the heat sink and fan on my Deluxe and it runs much cooler than the passive system on my premium with more stress actually being placed on my Deluxe board. I'm considering removing the passive cooling on my premium and adding a fan to it as well. Perhaps the connections are for those purposes.

 

[Habanerosky]

i have the same mobo, but i have a lot more hooked up to it (see specs). Mine also gets to the 57C range, is it possible that it is just how hot the mobo runs? (although the included asus software freaks out when it gets past 55)