Help with wattage, will this PSU work for this setup?

Yes your MAX will be at like 175

You should be okay. Check out this calculator to get a conservative estimate, but remember that this would be for everything pulling it's max power at the same time.

The most power is normally consumed at boot time when everyting is starting up esspecially HDDs, CD and DVD drives in addition to the graphics card the CPU and memory.
I did't understand your comment about your HDD.

Realistically speaking, full load for that system will probably be around 100~120W. I wouldn't really stress it beyond that. The power supply is Allied and they're not really known for quality. I seriously doubt it's able to supply its advertised rating of 275W.

Get a passive HD5570, no need for an active cooled one. Replace the CPU with a AMD x2 240e/245e , a 45W CPU basically. The PSU should do fine, although as ilovejedd said, going with a quality PSU would be best.

You could go for a smaller mini-ITX build if you don`t plan on stuffing alot of HDDs in it, basically AMD x2 + mini-ITX mobo + 2GB or ram + Antec ISK 300 or a Core i3 sistem.

Unless you are hard for space avoid the slim cases. It limits your choices on some video/tuner cards.

Without knowing the make/model of your HDD we have no idea how much power he draws normally. HDDs use a lot of power to spinup at boot time.
Many power supplies are rated by their max input power and not by the amount of ouput power they can provide. Some are much more efficient then others meaning that the amount of output power available is a higher percentage of the max input power then for other supplys.

Here are actual measurements of DC input to the system from the PSU (that's what you need to know when you choose a PSU).

- Athlon II X2 250
- 785G mb
- DDR3-1600 2 x 1GB
- HD 5570
- 1 x HDD (WD Blue 640GB)

	DC Input
Idle	50W
BD Playback (with PDVD+ISO)	61W
SD Playback (with ffdshow+Avisynth)	103W
x264 HD Benchmark 2nd Pass	104W
Prim95	114W
FurMark Stress Test	114W
Prim95+FurMark	140W

So 140W is the max power draw of the system (but max CPU load + max GPU load is a highly unpractical senario). Add 6-8W for each additional HDD (most current HDDs draw < 8W at seek). If you add an internal (single) TV tuner, then

	DC Input
Idle	53W
Watch	65W
Record	55W

Computer power supplies are *rated* based on their maximum output power. Everybody (should) knows this, for example, from measurements like below. Inflating ratings may not be uncommon, however (in particular in cheaper PSUs).

It's Allied. I think they pull their ratings from a magic hat. Alas, the PSU is SFX and there aren't that many replacements available for those not to mention a replacement would probably cost more than the case itself.

Here are typical techniques to inflate ratings:

- Advertising the peak power, rather than the continuous power;
- Determining the continuous output power capability at unrealistically low temperatures (at room temperature as opposed to 40°C, a more likely temperature inside a PC case);
- Advertising total power as a measure of capacity, when modern systems are almost totally reliant on the current available from the 12 volt line(s). [Advertising total power is normal, of course.]