Hi guys i need a little help on deciding what psu i need for my pc. I think it is very very underpowered for that stuff i have in it. Here is a spec sheet of what is in it, also there is 4 120mm fans and a Asus Silent Knight II cpu cooler, here are the specs sheet i would all so like to remove the 4 gb of memory of and replace it with 8gb of dd2-1066 aswell as crossfiring a ati 3870hd (i have one all ready in the) so i would need 2 6 pins for the graphics and one 8 pin for the motherboard. thanx guys
There is no point crossfiring the HD3870s. The HD3870 is no more powerful than an HD4670 you can buy for $60 that uses a third as much power. On top of this, one HD5750 is faster than two HD3870s or two HD4670s, and only costs $130. That will be much easier on your PSU. A lightly overclocked Q6600 with 4 HDDs and a single HD5750 will require a PSU of 300W. The same with two HD3870s will require a 450W PSU with two 6-pin PCIe power connectors. In these cases I would recommend a Corsair CX 400W and HX 520W respectively.
Don't use that PSU calculator, it massively overstates the PSU you need for your system. It gives you a 'worst case scenario' but only for when you've upgraded loads of components. A 250W system it will typically rate you a 400-450W PSU for, at the least.
Ok thanks for the help! I was looking at the two HD3870's as i thought it would be cheaper but i think i will wait untill the price drop in the new year for the HIS Radeon HD 5850 1GB. The psu i have is a trust 580w but it a cheap psu and i wan't something more stable for overclocking and as i say it need the 8-pin for the motherboard too.
Mike: Certainly Outervision in particular, but there is only one PSU calculator I've seen that's realistic, and amazingly enough it's this one: http://www.corsair.com/psufinder/default.aspx You would think that Corsair would try and exploit the consumer by advocating too much power, but this tester seems very accurate, the lowest rated PSU there is usually about right for the system, not underpowered, but not excessive. With a cheapo PSU like a Trust, you should definitely get a new unit as soon as possible. I stand by the PSUs I recommended.
The HD5870 is a spectacularly powerful card, but because it has no opposition ATI can really charge whatever the hell they like for it, thus it's way overpriced. The HD5850 is still 85% as powerful, and only costs 70% as much.
Not really. The only time I would recommend it is for top-end crossfire configs, you want the absolute fastest currently possible.
