How Much Is Too Much???????

[paupton]

If I have a 300 watt psu how do I know when I have reached the threshold on power draw on the PSU? Do I add up the watts or the amps draw from all the devices combined. Would this be an accurate gauge. Also how much does a XP 1700 with a Ti 500 GF3 draw from the PSU.? If we could get a figure for the MOBO and VGA I would know how much reserve is left for the drives etc. Also how much power does a HDD, CDR draw. I can find the draw in amps but nothing in watts. If the PSU is rated for 3 volt 16 amp, 5 volt 30 amp and 12 volt 11 amp output is this a combined total.
Some of electrical engineers please respond. I know that the psu cannot be overtaxed and still adequately supply the MOBO with the power it needs to run properly.
WAITING........................................... .................................................. .................................................. .................................................. .................................................. .................. . . . .

[Warlord2]

you will know if you reached the threshold if your computer is unstable or locks up for no reason or when its under load

I recommend atleast a 350watt if your doing xp and a gf3 sense those are both power hungery