How do you know when to get a bigger PSU

[rainkiller]

can some one please tell me how do you know or find out when you need a bigger PSU in you comp?
i'm not so sure how big of a PSU i'll need for my new comp, so how could i tell and find out wheather the one i have in my comp now is big enough!

 

[Cache]

can some one please tell me how do you know or find out when you need a bigger PSU in you comp?
i'm not so sure how big of a PSU i'll need for my new comp, so how could i tell and find out wheather the one i have in my comp now is big enough!

List the specs for your new computer, it makes it easier to determine where you're going with the power. It also helps to let us know what your current PSU is. Generally speaking, calculate the max wattage pulled from the components of your new system and assume any future upgrades you might intend to make with the system. Personally, I've got a 750-watt even though I could easily knock that back a couple-hundred watts, because inevitably I amd going to find things to add, and I'd rather have the extra headroom in there (plus it's hotter than hell in the summers here--consider how warm your room gets when you build (although that's more of a personal mantra for me, as... well, it is unforgivably hot in the summertime).

 

[rainkiller]

the one i have right now which i'm still putting toether right now is:
this is one i'm not sure if the PSU is big enough for:

Q6600
4gb 1600 mhz ddr3
512mb 8800GT but soon(1 week getting 1gb 9800GTX)
GA-EP45T-UD3P
12 hundred case so tonnes of fans

PSU is ONLY 400Watts
but i'm pretty sure it should work!

 

[Cache]

the one i have right now which i'm still putting toether right now is:
this is one i'm not sure if the PSU is big enough for:

Q6600
4gb 1600 mhz ddr3
512mb 8800GT but soon(1 week getting 1gb 9800GTX)
GA-EP45T-UD3P
12 hundred case so tonnes of fans

PSU is ONLY 400Watts
but i'm pretty sure it should work!

I'd need a brand on the PSU--it helps to identify what kind of workload it can really pull, but consider that with the videocard and quad core running an intensive 3D game, that 400-watt PSU is going to be sweating buckets trying to give the system all it wants. Also, there is no wiggle room. You want to add a hard drive? Case lights? Sweet new USB toys? Overclock any of the components? That power supply isn't going to be able to do anything for the future.

Other people may have different conclusions, but I like a PSU with some overhead. If you ever swap that 8800 for a newer video card, you'd have to get a new power supply anyways. Personally, I'd look for something with at least 600 watts, just to be on the safe side.

 

[rainkiller]

yer 500gb hard drive and all fans have blue LEDS, so you reckon a 600w, but that way i will have room for the new video card to yer!
also over clocked to 3ghz CPU, might go for 4GHZ since i problay can, but power supply might not handle