Hi guys. I have a HTPC system I put together from odds and ends I had laying around essentially. I realized last night that I had literally every component I needed to finish the project and get the system up and running, except for the PSU. I'm intending to purchase a Seasonic S12II 430w, although the Antec Neo Eco 400w is on sale for $40 at Newegg and seems tempting.
In any event, I remembered that I had an unused Antec Basiq 350w sitting in an ancient HP I'd failed to revive, so I pulled it out and got everything up and running. According to the online PSU calc's, I am JUST under the rated power for the unit. I am fairly sure that I won't hurt anything running this way for a week or so until the new unit is delivered, but I would actually feel better hearing someone else tell me I shouldn't just shut the thing down and wait.
Asus M5A88-M motherboard
AMD Athlon II 455 CPU (stock 3.3 clock)
Asus HD 6670 GPU
Crucial Ballistix 8gb (4gb x 2) 1333mhz 1.5v
Intel 330 120gb SSD
WD 500gb Caviar Blue
Asus DVD+R DL burner
Logisys Beta 400 ST cooler
120mm CM intake
92mm Silenx exhaust
You should be fine of running it with the BP-350, I believe those calculators give you a bit over the actual wattage.
Edit: Your CPU uses around 95 watts, the GPU is around 65 watts which comes to 160 watts. Add all those small things and you should still be perfectly fine, if you were going to overclock then there may be a problem but you are fine for now.
For a system using a single Radeon HD 6670 graphics card AMD specifies a minimum of a 400 Watt or greater power supply. The power supply should also have a combined +12 Volt continuous current rating of 19 Amps or greater.
Total Power Supply Wattage is NOT the crucial factor in power supply selection!!! Total Combined Continuous Power/Current Available on the +12V Rail(s) rated @ 45-50°C ambient temperature, is the most important factor.
The Antec Basiq Series 350 Watt (BP350P), with its combined +12 Volt continuous current rating of 23 Amps, is sufficient to power your system configuration with a single Radeon HD 6670.