I think the only way you can run Quadfire or SLI quad is with 2 dual gpu cards. There are only 2 SLI connectors on powerful cards allowing for a maximum of 3 single gpu cards to be connected together. Each dual card would only draw up to 75 watts from each slot. 3 single cards could draw up to 19.5A (20.33 for tri 88/9800gt's) so your PSU would quite happily handle a Tri card or quad (using dual cards) setup
Looking at the specs for the Antec Truepower New 650, the 8 pin connectors are actually 6+2 pin connectors so you wouldn't have to worry about not being able to use them. The 8 pin CPU connector has it's own rail so you won't have to worry about using too much power from it as the motherboard designers would have taken the maximum current draw into account. You tend to see boards with more PCI-E connectors having an additional Molex connector if they require more power anyway. I would say you should be fine with whatever connectors you use. If you do plan on some extreme overclocking you may need a new PSU though as the max the 8 pin can draw is ~300W or 25A.
I think the extra molex connector is on boards that were in the transitional period between 20 and 24 pin, so they could power the slots without blowing the wires, I've not seen any recent boards with the extra molex. I was talking about the modular cabling on the PSU end which has 6 pin sockets for drives etc on rail 1 and 8 pin sockets for the GPU's. I wonder if it is physically possible to plug a 6 pin into an 8 pin socket? Back in a minute.....
If you mean the 6 pin PCI-E connectors then yes, you can. You card may not like it though as some detect the extra pins.
My GPU's have 2x 6 pins each. My PSU on the other hand is partly modular. The essentials (24 pin, 2x PCIe connectors and an array of Molex/Sata/floppy connections) are wired directly into the PSU, as is the 8 pin EPS. I can attach additional Molex/Sata connectors by plugging them into the 6 pin ports on my PSU, but these would all run from 12v1. The additional 2x PCIe connectors can also be plugged in to 12v4 which has 8 pins. I've just discovered that it is physically possible to plug a 6 pin drive connector into the 8 pin 12v4 rail and all the wire colours match up except for the bottom right which is green & yellow on the 8 pin, and black & yellow on the 6 pin. So there may be extra room for manuver if I was to upgrade to a single GPU card. but i'd have to double check to be on the safe side. (Edit: the manual says it is possible.) The PSU limits it at 22A (12v2) so 264w. I'm pretty sure a 95w processor wouldn't come close to this even when overclocked. I only intend to overclock it to the point I could happily use it on a daily basis without worrying about temperatures or component stress. 3.8 is more than enough for now.
Ok, I've just bought the Maplin equivelent of the Kill-A-Watt which has put this whole thing in persective, if it is accurate that is. When running furmark and Prime64 the readout from the wall maxes out at 492w which at 85% is 418w from the PSU. Crysis only draws around 330w from the wall and 280.5w from the PSU. (this is overclocked to 3500 with turbo and the same voltages i'd usually use at 3800, I'm still waiting for the replacement for the ram I rma'd to arrive so I can clock it back up) So in general gaming use it doesn't even reach 50% of My PSU's capabilities. If it is reading accurately that is. Anyone with a similar rig getting similar readings? Edit: In fact after plugging the power from everything that is attached to my computer into the power monitor, including a 22 inch LCD, external Hard drive and 4 amps attached to 10 speakers and a sub (at a volume level that if it were any more, i'd have to start selling tickets to the neighbours and get an entertainment licence) it still doesn't go much above 450w from the plug when playing crysis! Edit: the highest recorded peak for normal use (i.e. not prime 95 and furmark) so far is 378w which at 85% is 321w whilst playing starcraft 2 Spoiler (Last of the protos' missions) . Almost dead on 50% total PSU output. Edit: The normal use peaks are with Vsync enabled. It seems that when Vsync is disabled and frame rates aren't limited, then power draw can be much more. For instance with vsync enabled, Prime64 on 4 threads and Furmark in multi gpu mode draws 60w less from the wall (53 less from PSU) than it does without Vsync. Edit: These figures are all at 1680x1050, I'm sure if I had a higher resolution then the graphics cards would draw more power. Also the reading on the power meter only updates once a second (would be hard to read in real time) so this may not record every peak.
Only £7.99, I think they do a £15.99 one as well that can handle 15A from the plug instead of the regular 13A.
