What is the difference between a 300 watt psu and a 400 watt psu?

[fatbaby]

Other than the obvious...I assume the 400 watt psu just has more connectors than the 300 watt?

 

[PCHPlayer]

100 Watts Hey someone had to say it. Theoretically a 400 can provide a more even current under heavier loads. Which means you won't see your voltages drop when a CD burner kicks in. Each PS model is different and a 300 from one manufacturer may provide a cleaner current under load than a 400 from another. As for connectors, I think that is just up to the manufacturer.

 

[ubersam]

<< a 400 can provide a more even current under heavier loads >>

Not exactly. A 400 watt PS will give you more [power] headroom for additional power consuming components (i.e. HDs, PCI/AGP cards, Fans). Taking a look at 2 common PS from a well known manufacturer: the 400w PS provides a combined 5v / 3.3v power of 245 watts max, while the 300w version only 160 watts. Also, the 12v output of the 400w can provide up to 144 watts max while the 300 only 120 watts.

The 'even'-ness of the current is more of a product quality issue than of a power. One manufacturer might use higher quality components (for filtering, regulating or buffering) than the next.