undervolting hd 4850 to run on 200w psu

[geofrancis]

i have recently upgraded my server in my morex 669 itx case the problem is it only has a 200w psu and im starting to reach the limits of it with what i have installed in it.

phenom 9150e 65w undervolted to 1.05v @ 1.8ghz
J&W Mitx 780g htpc board
4gb ddr2 800 (2x ddr2 800 so-dimms)
5 x 3.5" sata hard drives
2x usb dvd-rw's

at the moment im using the 780g onboard graphics but i have a hd4850 that i want to install in it but i dont think that the power supply is up to the job because i hooked a kill-a-watt up to the computer and its saying its using 138w with prime 95 running and 122w with prime 95 + furmark so now my problem is i only have 60 or so watts to play with.

as far as i know a hd 4850 uses about 110W full load but how far can this graphics card be undervolted at stock speeds and underclocked and how much power will it save?

if that fails i have an external ac to 12v 120w adapter that i could wire up to power the graphics card via the pci-e power cable but will that be enough?


pic of the case