New Computer

[Nullflare]

Hello, I am looking at a new PC rig. Planning to include :
Motherboard: Gigabyte 78LMT USB 3.0 Motherboard Technology
Processor: AMD Bulldozer FX 8120 3.1ghz 8mb Cache
RAM: 16gb DDR3 1600mhz Memory
Graphics: ATI Radeon 6670 2gb.

Am just wondering if a 500watt power supply will be enough to run this? I know the basics of pc building, but when it comes to the electronics i am at a loss. There's a difference of about £50 between a 500w and a 750w and am wondering if the 500w will support all the basics? Not overly worried about overcocking possabilites, as what i have planned for the pc, the general settings is more than enough

 

[Onus]

If I can, I'd like to talk you out of those choices, or at the very least make you aware of what you are getting.
First of all, the motherboard is obsolete. It is centered on older technology that has been patched to work with AM3+. Rather than offering 5200MT/s (or even 5600MT/s) it only has 4400MT/s; this speed affects data throughput between the CPU and various devices on the motherboard.
Second, Bulldozer CPUs have been pretty much universally criticized as power hungry, hot underperformers for most tasks, especially typical desktop software (e.g. games) that most people run. For most things, a last generation Intel i5 will be notably faster in most things: http://www.anandtech.com/bench/Product/434?vs=363 (shows the FX-8150, which is faster, but the FX-8120 should easily reach that speed).
If you strongly prefer AMD, then get a Piledriver CPU. Current generation Intel i5's have their way with them too, but the difference is typically not as dramatic unless the i5 is overclocked.
Third, if you want this for games, you need a stronger graphics card unless you'll be playing at very low resolutions like 1366x768 and don't mind turning the settings down a lot. I would recommend either a HD7770 or GTX650Ti as a comfortable minimum for games.
Finally, a quality 500W PSU is easily enough for any of these suggestions. Look for 80+ certification (not so much for the efficiency, but because it was run at 100% load during testing, which would kill junk), and confirm it at www.80plus.org. I would recommend anything built by Seasonic, or new FSP, new Rosewill, or Enermax/LEPA.
Finally, you can save some money by getting 8GB of RAM.