Amperes ratings for the 12V is much more important; this powers the CPU and GPU, which consume 80-95% of power in a typical system.
In general high quality power supplies will have more amps over the +12V rails than cheap ones; Most of the 400W or 450W (36-38 amps) is over the 12V rails for good PSUs while your 500W generic brand might only have 250W or 300W (20-25 amps) over the 12V rails. For a single card video cad you would want 350W (29 amps) or more over the +12V; for SLI/CF you would want over 500W over these rails.
just because it says 500w doesnt mean it can produce 500w continuous power. Cheap power supplies like that are rated in PEAK power and will likely only deliver around 300w continuous. an Antec Earthwatts 380w will be able to produce more continuous power than that crap "500w" psu you have.
A 768GB GTX460 and a HD5770 perform similarly. The 1GB GTX460 is a little stronger, but "beats the piss out of" is an ignorant [noobish | fanboy] remark.
I would not trust that PSU, especially with a GTX460. If it can't hack the load, and blows, it will probably take other parts with it; that's not a risk I'd care to take.
Replace your PSU first. A quality modern PSU has full range active PFC (no little voltage switch) and 80+ certification. Antec, Seasonic, Corsair, Enermax, and XFX are among the better brands.
so i don't want an expensive psu, just something that will hold this system with a good graphics card, and that Radeon HD 6850 - my cpu could bottleneck it, no?
i'm a completely noob in pcs :|
You can't get too good of a graphics card, don't worry about a bottleneck, it's an overused term and the concept is only usefull in matching parts so that you don't waste money in a build, it's not like having a better GPU makes your CPU perform worse, you will just have extra overhead and the GPU might not be fully utilized all the time, but if it's the same price as an inferior one who give a crap.
Both the 460 versions are significantly better than the 5770; if you can't accept that then you've obviously got your thumbs up AMD's ass.
They aren't even comparable; the 460s compare to 5830s and 6850s.
Anyone who doesn't pony up $15 for the 460 over the 5770 is mentally retarded.
fair enough its faster, but where im from its about $50 difference between the 5770 ($127) and 460se ($179), the full 460 is another $20 again. Im amazed the pricing where your looking is so close. Are you finding the most expensive 5770 vs the cheapest 460?