dc 7700 sff pciex 16 power problem

I have a problem with HP DC 7700 SFF, the specs say that the 16x
pciex slot is assigned a maximum power of 25 W and so I could
install in the best case a Radeon HD 5450 which is in the limit of
25 W but is not a big difference from my current video card a hd 4350 .
My question is what happens if i install a video card with a
maximum consumption of 35 W because if you calculate the total
power remains quite enough for a better card.

my configuration

-power source 230 w (80 plus)

-processor > celeron e3400 …65 w max

-memory > 4 gb 667 mhz …20 w

-two hard drives …20 w

-motherboard intelq965 chipset …20 w

-no dvd writer (disconnected)

                                                      -----------
                                                         125  (+/- 10 w)

iff the power source can give say 200 w real power would still be enough

please someone help im quite desperate !!!

A PCI express slot will deliver up to 75W of power. However, if the card need it’s own power source directly from the power supply via 6/8-pin cables, it uses much less power from the slot (25-30W), and more from the power supply.

PCIe’s can deliver up to 75W, so you should have no problem installing this card which AMD specifies has a typical load of around 19W.