"limitations of OPUS 150W dc/dc" i bet it makes **** coffee and won't be much company on a lonely winters night.
It should run that i think but we need more specs.
ie what pci cards
what hard drives and how many
same for optical drives
your question is a bit too vague. Have a look at some other systems on here, a few people with hight power are considering dual opus or you might have to power your drives from another seconday psu e.g. a 90W one. There is a power calc outhere somewhere and there will be a link to it if you search (i aint finding it for you i spend far too long on this forum) but i suspect your cpu will draw somewhere between 60-80watts alone. There is an Opus 200w coming out and that should be fine.
it will show you the "max" power of a psu you should have
on the spec manual of the opus it lists the max current at each of 12v, 5v, 3.3v, etc. I added up the watts of each max value and found 190 something... the above tool told me My p4 2.8 setup would need 175watts max, so i figure that should work
on another note do you need 2.8ghz? you may do and each to their own if you don't then don't use it yo will just be putting uncessarsary load on your PSU and taking power that drives or PCI cards may need.
there might be solution...Frys has cheap(45$) motherboards with duron(~45w)...before we order anything...we can go pick up a board there(if they still have it) and order the 90w psu..in turn makign the budget
You can't judge the appropriateness of the supply by the overall wattage. You need to look at it's capacity on each individual rail and compare that to your needs. Also be aware that some supplies have dependencies between their rails such that there may be a maximum combined power rating. To my knowledge the Opus 150w has independent power rails. I have no idea if it will power your system but others have reported some success powering P4 systems with it.