eVGA overly cautious on power requirements?

[n64jok]

I have an Antec SP400 (400W) PSU, which supplies a max load of 10A on the 12V1 connection and 15A on 12V2 according to Antec (http://www.antec.com/specs/SP400_spe.html).

I was going to upgrade to an eVGA 7950GT, but it requires 20A on the +12V rail for a non-SLI setup according to eVGA's web page (http://www.evga.com/products/moreinfo.asp?pn=512-P2-N635-AR&family=22).

I'm wondering if eVGA is being overly cautious about the +12V requirement of 20A. For example, I noticed that several of the well known Antec PSUs, such as the Phantom 500 and Neo 550W and TruePower Trio 550 also don't supply 20A (although they do go up to 18A).

Any advice would be appreciated. Anyone running an Antec SP400 with a 7900 class video card?

Here's what else is in the computer:

Antec SmartFan 80mm Case Fan
ASUS A8N-E Athlon64 ATX Mbrd
AMD Athlon64 X2 Dual Core 4200+ (2.2GHz, 512KBx2), S939, 90nm
2GB Corsair Value CAS 2.0
2x Western Digital 250GB SATA II
Sony 1615 DVD
NEC 3550A DVD R/W

I also have an old Creative Soundblaster Live card I want to add, but that's it.

Cheers,

JK

 

[Sedako]

The recommendation of 20A on the 12v rail is the total power output. 12v1 (10A) + 12x2 (15A) = 25A total. That means you should be fine.