weak 12V rail?

[Lifthanger]

Hi.
I've got stability problems with my system.It fails the second prime95 test, which uses the most wattage.
My 550W PSU:
12V 24A with multimeter 11,97V
5V 40A 5,17V
3.3V 32A 3.36V
combined 305W
only 3.3 has sense wire.
my system is a gigabyte ga 7n400L
with mobile XP at 11*200 and 1024MB ram
2 cdrw + 2*harddisk
9600xt 128MB
when under load the 12V rail drops slowly to 11,89V and I'm sure it would drop further if the prime test wouldn't fail.
All of my components seem to use the 12V rail: cpu,gfx,fans,drives
and I think under load(heat) the power is just not enough to keep it all stable.
but If 24A are not enough for a small system...
since I've got no 12V sense wire, I can't do the mod.
Is there some way to make it work?
other mods to increase 12V rail?
Or some way to let the almost unused 5V rail support the 12V rail?
Why do these **** take 40A on the 5V which is barely used..? wtf?

[STEvil]

you sure vdimm isnt drooping under load?

Try 11.5x192 or loosen timings a notch.

[Snowman89]

my 12v dropps to 11.43 without load with 2500+@2.5ghz (225x11) 2vcore gf4 ti4200, 512mb bh-5, 7fans dvd reader, all that and some more on a 300w :)

[Lifthanger]

according to mbm5 my dimm voltage doesn't move a bit.And my ram is Twinmos
PC3200 at 2,5-3-3-11 .. it survives the 3rd prime95 test which stresses ram and memtest... but I'll try it.

[Jesus]

Don't belive all what MBM says. Your sensor chips on the MBO may be reading faulty and then the redaings in MBM are also faulty, get a Mutimeter stick it into a Molex and check your Voltages.

[Lifthanger]

If you read my first post, you'll see, that I've already measured my rails with an multimeter at a molex connector.
I should try to find a way to measure vcore and dimm voltage on with the multimeter.

[Jesus]

the reply was more for snowman99.
Usually U have a reding point near the sockt look for a Moffset base a silver square and two soldering points a bit loer of the square paralell to the edges of the sqaure.

[STEvil]

try test 5, it fails before any other tests for me.