Quick PSU Power Rating Question

I need a 350W PSU however from some of the reviews and forums I have read, it seems that it might be better to buy a lager psu for it to run at 30 - 50% of its Max rating. For example get a 600W PSU and it will be very quiet running away at 250W


Is this correct or should I size my PSU according to this (http://www.extreme.outervision.com/psucalculatorlite.jsp) and get a 350W - 380W PSU when it says I need 320W

Thanks

If I were a normal computer builder and I knew I needed 320 watts from a PSU, I'd get one of these:
http://www.newegg.com/Product/Prod [...] 6817139008

One of the reasons I like Corsair PSU's is that their entire line is very conservatively designed. They are all good for 15% - 20% more power than they are rated for at 50 C, not the usual 25 C.

AndI tend to overspec power supplies primarily because of my military electronics background. My goal is to operate a PSU at around 50% - 70% of capacity.

If i were in your position i would but a nice 450-500 watt power supply, the reason being that you never know what you will want to do in the future as you may want a CPU mobo or GPU upgrade and have to buy a new power supply.

Also you have to take into account that if you run a power supply at 80-90% of its maximum capacity for a long time you have a better chance of it wearing out, overheating your system, or just burning up.

But if you know you arent going to be upgrading it then you may be fine with a nice 350W.

PS: GET MODULAR!!!! they may seem like a waste of money but they are lifesavers if you want to wire your case nicely and therefore restricting less airflow and keeping your system much cooler.

thanks for your help guys, some good opinions. I am in the UK therefore that exact psu from newegg.com is not going to happen. But I can buy the same thing over here (http://www.ebuyer.com/product/150985) . I was looking at the OCZ Stealth Stream 400W (http://www.ebuyer.com/product/152505) as well. Both in my price range. Just want the one which is the quietest. Need to get this purchased sharpish, probably today/tonight.

Thanks Again