ok i bought an xclio 450w for my x1800xt 512mb. i replaced my old 300w with the xclio but once i turn the computer on, the cpu fan spin for 1 sec and stop and nothing else is seen. the gateway button light in front of my computer is lighted but nothing on monitor or anything. i cant hear even the power supply fan. i think its a dead psu? once i put my old psu on everything work fine. ok so i was pissed that i wont be able to use the x1800xt so i slapped it in with the old 300w. nothing bad happen. in fact im using it now as i write this. the thing is the 6900 3dmark05 score!!! this thing should be getting 8900+. lastest driver too. now the question is, can low power supply really ABLE to put out low performance? or is it something else.