How much power do I need?

M

mister2cool

n00b
Joined
Nov 26, 2004
Messages
18
My video card is complaining that it doesn't have enough power!!!! HELP!!!!

I have a Vigor 550W PSU, and here are what it is driving
CPU: P4 Socket 478 3.2E
Mb: Soyo i875 Dragon 2
Hitachi 250GB SATA hard drive
Maxtor 250GB SATA hard drive
DVD-RW drive
2x 120mm cooling fan
ThermalTake Bigwater II water cooling kit
Nvidia 6800 Ultra

Problem started when I plugged in the Maxtor drive. Can anyone give me an estimate how much power I need to run all these? I actually have another hard drive that I had leave unplugged or it won't even turn on.

Thanks in advance for any help!
 
CPU\mobo?

the CPU is likely the single most power hungry component ;)
 
http://www.xbitlabs.com/articles/video/display/ati-vs-nv-power_2.html
http://www.xbitlabs.com/misc/picture/?src=/images/video/ati-vs-nv-power/6800u_table-b.gif&1=1

theoretical (never happen)
http://takaman.jp/D/?M=PcbAIQbeHdSAgHKT4kG5@BDkHkpG5HTZAZavHHMZ&english
note modem = pump 24W (worse case)

Realworld worse case draw (post spinup and pegged CPU\GPU no optical)
+3.3V\+5V = 70Watts
+12V = 220Watts (18.5A minimum)

now the trick is to find a PSU that will meet that load at your operating temperature
and maintain as stable a load as possible

pretty much any ATX12V v2.0 or even v1.3hybrid will do it
but there are secondary criteria like
power quality vs budget
sound level & efficiency
features\esthetics
upgrade path (PCI-E in 75W or 150W or SLi or G70)

now the Vigor which I dont see in a 550 just a 500 is an older ATX12V v1.3, (not a hybrid) and is mostly bling bling
MGE isnt known for their "great" supplies
that one with only 19A on the +12V rail before derating for temperature isnt up to the job obviously,
given its likely operating temperature its more likely to be around 11>13A (50C>40C)
whereas its was rated at 21C=19A probably
so when you actually start to peg the CPU\GPU your overtaxing it.
 
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