GT 640+Q8300 on a 420W generic PSU

[NVIDIAFTWGuy]

Hey guys, i'm about to put a new gpu and more ram into my old core 2 quad system.

Specs as follows (currently)
Intel Core 2 Quad Q8300 (no oc done)
oem g43/g45 board
2 gigs of DDR2
some 250W psu
2* WD Digital 640GB
Optical drive

What i'm planning to upgrade to:
GT 640 (ddr3) (128bit)
+4GB DDR2
420W psu

More detailed specs of PSU
12v rail
+12v1=10a
+12v2=12a
-12v=0.5a

+5v=12a
+3.3v=16a
+5vsb=3.0a

 

[ghettogamer]

if its an OEM psu then you can trust the rating , but if its a cheapo no named or unknown brand , I would test the rails or buy a better one

 

[Eximo]

Hmm, are those numbers for the 250W PSU or the 420W? If they are for the 420W PSU, that is actually closer to a 250W PSU in 12V output.

Q8300 is rated as a 95W CPU. GT640 DDR3 ranges from 50-65W depending on the exact GPU. So worst case would be 160W without fans, drive, motherboard, and memory.

It would likely work, but I wouldn't want to use that system for anything like 24/7 usage.

 

[NVIDIAFTWGuy]

Hmm, are those numbers for the 250W PSU or the 420W? If they are for the 420W PSU, that is actually closer to a 250W PSU in 12V output.

Q8300 is rated as a 95W CPU. GT640 DDR3 ranges from 50-65W depending on the exact GPU. So worst case would be 160W without fans, drive, motherboard, and memory.

It would likely work, but I wouldn't want to use that system for anything like 24/7 usage.

It's for the 420W psu. For a PSU rating of >350W, how much +12V output should I be getting actually?

 

[Eximo]

Hmm, are those numbers for the 250W PSU or the 420W? If they are for the 420W PSU, that is actually closer to a 250W PSU in 12V output.

Q8300 is rated as a 95W CPU. GT640 DDR3 ranges from 50-65W depending on the exact GPU. So worst case would be 160W without fans, drive, motherboard, and memory.

It would likely work, but I wouldn't want to use that system for anything like 24/7 usage.

It's for the 420W psu. For a PSU rating of >350W, how much +12V output should I be getting actually?

These days within 10% of the overall PSU output. Contemporary computers run almost exclusively on 12V, a little 5V and a small amount of 3.3V. Really, the circuitry runs around 1V-2V and the incoming power is converted by voltage regulation modules to what the system needs internally.

Power supplies like that 420W are just older designs. The intention is that the un-informed can pick up a power supply at a store and drop them into older computers without issue.

'Good' power supplies are rated only by 12V output. So a 650W Corsair RMx is rated for 648W of 12V output, and only a total of 130W output for 5V and 3.3V.