Thanks, that calculator was helpful. I came to 476w after factoring in the surge compensation(25%) and capacitor aging(20%). I wasn't sure what TDP was so I left it at 100%. I went ahead and ordered the 500w last night...I guess it works out to be ok.
That should be good although i think 550w woulda been better, however that calcualtor shows worst case scenario so you'll be fine.
He could have bought a 350w PSU and he never would have hit the max. That calculator said I need almost 285w (400w if I used the extra buffers that they recommend), yet my system never pulls over 165 watts (maybe 175 since i haded a new HD last week).
That calculator (and every other one I've seen) overstates power requirements by 70% or more everytme(far more if you add any cushion for Surg/capcitor aging).
no the calc is generally correct. It calculated if everything was running and running at 100%. While i do agree its off its fairly close. When u boot ur PC every thing runs at 100% so in that sense yes the calc is pretty close.
Even then it's not correct. First of all, your GPU isn't running at 100%. It doesn't take much to display the CGA graphics that you see when the computer posts. graphics cards 26 years ago could easilly have handled it.
Your CPU is not at 100% until long after your HD's have spun up.
Hard Drives take more to spinup than they do in normal use. However, that's barely double what they use at idle, which means for his drive it's maybe drawing 20 watts when it spins up...and that's for what, 5 or 10 seconds? He's got one drive he may buy a 2nd. That's at most 30 extra watts at peak.
DVD players spinup a little at boot, but it's negligable (maybe 8 watts). However, if you're booting from CD/dvd, then it's 15 watts. DVD players spin up after the HD's, so the peak load from the DVD is after the peak draw form the HDs.
I've got 6 fans and I can shut 4 of them off via software (the others are hardwired at 7v). If I go from Off to Max RPM on the 4 fans it's an 8w difference peak.
The only major draws on his PSU are his CPU and his Video card. If he had an array of HD's, then that'd be a draw at start up, but even the HD makers say if you have lots of HD's, you should stagger the spin up, rather than by a bigger more expensive PSU to meet the needs of a spike that lasts a few seconds at boot up (a configurable option which is available in most, if not all modern BIOS menus).
Finally, good PSUs are rated for constant loads, not peaks. So even IF some how we all managed to buy the most incredibly inefficient drives and our systems somehow managed to pull 420 watts at boot up, an Antec, OCZ, Enermax, Fortron or seasonic (to name a few good ones) rated at 400 watts could handle it.
Now I wouldn't recommend one cut it that close, but I'm just illustrating how completely out of whack things have become. You don't need 100% more than your peak loads, much less 150% or 175% more.
I don't think I'm missing anything on the boot up, but it's certainly possible.
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