best psu's available for undervolted system.

[Lostfaith]

Well basically as you can read from my thread in the amd section I have built a small and primarily quiet 24/7 torrent/internet on the go and server system.

These are the components:

Cpu: 4000+ Brisbane running at Crystal 'n Quiet with 0.816V @ 1GHz - 0.992V @ 2Ghz
Motherboard: Asus M2A-VM with the 690G chipset. running the onboard video.
RAM: single stick OCZ Gold XTC 800Mhz
HDD: WD 250GB S16 sata.
and a LG optical DVD/rw drive (Eide)
2 120mm fans.

currently I'm running a 300watt generic and inefficient Q-tec powersupply with a loud 80mm fan so I'd rather have a nice low wattage and ~80% efficient 300-400 watt model with a silent fan.

[mpilchfamily]

Then go with the Antec Earth Watts PSU. They have a good effieciency rating. Now if you want a good effiecient PSU that is quiet then the Phantom may be the PSU for you.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817103926

Yes its a 500W unit but PSUs are at there peak effiecency when they are kept cool, and only have a mid range to mid high range load on them. So a 500W unit may be perfect for you. Remeber the PSU is only going to supply what the system needs. So a 500W unit isn't going to be pulling more power then a 400W unit on the same system unless the eifficiency is drasticly different between the 2 units.

[Lostfaith]

tnx MP

I basically gave out a bit more and got this one: http://www.coolermaster.com/products/product.php?act=detail&tbcate=22&id=40

[Soulburner]

My Corsair 520/620 are nearly silent. No longer is my PSU the loudest part of the system...I can actually hear my HDD clicks again, and its even a quiet Samsung HD501LJ drive.

I vote Corsair HX520. Its modular, cheap, quiet, and extremely stable and efficient. With the rebates out there at ClubIT, you can get one for $99.