The manual says:
To meet expansion requirements, it is recommended that a power supply that can withstand high power consumption be used (500W or greater). If a power supply is used that does not provide the required power, the result can lead to an unstable or unbootable system.
I had a 350W and decided to get an inexpensive new one. If you plug in the options I use - and I run up to 9 hard drives in my computer - into a site for calculating power usage, it shows I need less than 300W. But I don't know a few things - like how much power the built-in video uses or whether my un-locked CPU draws more power.
I figure, you got a new computer because the old one broke or was too old - then it's time to get a new power supply. And why wonder if the odd problems you have are caused by a bad or underpowered PS.
http://extreme.outervision.com/PSUEngine
Here's everything I got - all from NewEgg except the drive I got locally at BestBuy
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
OK, the last one is the cool fans I got for my old tired case when ordered the cooler. Guess I'm old, but not dead!
I haven't installed that RAM yet, will get it tomorrow. Running some I'm not happy with cause I was trying to save a few dollars. They should fit under my cooler w/o problems, but we'll see.
If you decide to get a cooler - and you won't need it unless you decide to play with overclocking - might go for a bigger tube of thermal stuff. I was sweating making that one last. I think the Artic 3 is the favorite and might come with more. Some reviews have said that peanut butter works as well as some of this stuff and gives your computer a nice nutty scent!!
And hey, I'm just one person - old-time computer guru who's very out-of-date in building systems - but I have built close to 1000 in my day. And I did my research. I can't believe the ASUS fans haven't jumped in here with ideas. Or nasty stories about Gigabyte.
If you do get this and love it, you owe me dinner next time I'm in your hometown! Of course, I haven't left Texas in 10 yrs, so likely a good bargain. If you hate it, guess I'll change my name!