This is what it says on the sapphire product page,
–PCI ExpressR based PC is required with one X16 lane graphics slot available on the motherboard
–650 Watt or greater power supply with one 2x3-pin PCIeR power connector and one 2x4-pin PCIeR power connector is required (1K Watt with two 2x3-pin and two 2x4-pin connectors for ATI CrossFireX™ technology in dual mode)1
–Blu-ray™ / HD DVD playback requires Blu-ray / HD DVD drive
–For a complete ATI CrossFireX™ system, a second ATI Radeon™ HD 4870 X2 graphics card, an ATI CrossFireX Ready motherboard and one ATI CrossFireX Bridge Interconnect cable per graphics card (included) are required
Personally i would go with the 750 Watt unit, Make sure you get a good make/brand.
I would not use a 750w psu. Remember, it may need 750w but a 750w psu wont give you 750w. What is the efficiency of the psu? Calculate that into the amount and you will see how much the psu really gives.
So a 1000w that has an 85% efficiency (very high) give you a snug 850w at full load.
I hopes I'm right about this. Correct me if I am wrong.
Yea i saw the corsair but I am not too sure how things sit with a single rail , even one as awsome as that one
I did like the 450 for my last build but went for dual rail in the end. There probably isnt much in it though.
I have the 4870x2 and an Antec 650 Neo Power, works fine, never had a issue. If you do get it and do the fan fix, i would suggest somewhere around 50% fan speed, I had mine at 75% and it got a little annoying Playing HL
I just wanted to clarify this...
The 1kW PSU will very likely give all of the marketed 1000W to the system but it will draw more from the outlet. @85% it will draw something like 1180W from the grid
Really? I am intrigued. I can't wrap my head around that. Could you explain this a little more for me.
Where I am getting stuck at is that a 1000w PSU should produce 1000w. Is this 1000w from the wall or it gives you 1000w to use? I am currently under the assumption that it draws 1000w from the wall and gives you less to use.
It'll produce 1000W of usefull electricity for the system to use and since it's not an ideal component it'll draw more from the wall. The 'excess' is wasted as heat in the transformation process.
If it was the other way around, it would severely complicate rating/marketing of the unit as the efficiency of the unit varies under different loading conditions and typically is lower at the extreme ends of the range (at very low and very high loads). So you wouldn't really know what kind of output you would get with different units.
Probably not worth your time reading - if like you said - "CoolerMaster PSUs are cr@p"
Still HardOCP seemed to be toying with the idea of giving it the same award they gave the Corsair 750TX.
Which is a bit odd since I don't think you wanted to give the OP a recommendation for a cr@p PSU.
even an enermax pro 525w will power the system, just get a quility 600W+ power supply (or you already have one and you're checking whether it will power the system in which case it will don't worry about it)