Considering SLI Upgrade - Power requirements and questions

[ViperGTI]

Hi

I'm considering to add another MSI Geforce N560GTX TI (Twin Frozr II) to my computer to SLI.
I have some questions for the people who know or have perhaps done this. I'm more experienced on the software side than hardware.

1. Will I need a bigger power supply or will my current one suffice?

2. Is the increase in performance worth the price of the extra card?

3. I know that you cannot plug in a monitor on the second video card when running in SLI. However, I have two operating system partitions. I boot up in the one for work where I use 3 monitors and don't require SLI and the other one is just for gaming where the 3rd monitor is not required. Will something like this be possible with software configuration or something or will the second display card automatically disabled when the bridge connector is connected?


My current PC specs (in order to answer the first two questions)
CPU: Intel I7 2600K (overclocked to 4.2GHz)
Mainboard: MSI P67A-GD65
RAM: 12Gb DDR3
Display card: MSI Geforce N560GTX TI (Twin Frozr II) + Geforce GTS250 (will be replaced by new card)
PSU: Couger 750W
Drives: 1x128Gb SSD, 1x500Gb HDD, 2x1Tb HDD, 1xDVD Writer
Can't think of anything else to mention. Sound is onboard, no onboard display.

[Tank]

the 750 should be enough although if you can fit it in the budget try to get a 850w

[Patriarch]

Never heard of that power supply brand before, but if it's not well known, it's true output is likely nowhere near 750W. Always try for something like Seasonic (Antec and Corsair (except the GS series) are rebranded Seasonics) or PC Power and Cooling (OCZ) power supplies. They state their true power output.

Use this calculator, put it all you components and see what you'll need: http://extreme.outervision.com/psucalculatorlite.jsp

I don't know much about the newer Nvidia cards, but on my Radeon HD 5770's, you can plug the monitors into any ports and they will still work, in Crossfire. Also, Each card has 2XDVI, 2 HDMI and 1 Displayport port, should be more than enough to plug 3 displays into one card, if the Nvidia ones are the same.

[The Joker]

Never heard of that power supply brand before, but if it's not well known, it's true output is likely nowhere near 750W. Always try for something like Seasonic (Antec and Corsair (except the GS series) are rebranded Seasonics) or PC Power and Cooling (OCZ) power supplies. They state their true power output.

Use this calculator, put it all you components and see what you'll need: http://extreme.outervision.com/psucalculatorlite.jsp

I don't know much about the newer Nvidia cards, but on my Radeon HD 5770's, you can plug the monitors into any ports and they will still work, in Crossfire. Also, Each card has 2XDVI, 2 HDMI and 1 Displayport port, should be more than enough to plug 3 displays into one card, if the Nvidia ones are the same.

Just because you haven't heard about Cougar, doesn't mean that they aren't a well known brand, Infact the PSU he owns is silver 80 + sli/crossfire certified. Anyway...The Psu will be fine for that setup, You'll be pulling maximum of about 650w under load, well that's a gestimate.

As for the 2nd question...OMG yes lol 2x 560TI cards will eat a GTX580 without breaking a sweat.
Not to mention the 2 GIGS of Video Memory, which will be great if you plan on running massive resolutions. Its a worthy upgrade.

[ViperGTI]

ok, thanks... I'll do some looking around and see what the card cost these days. Used the calculated and my psu requirements come to approx 680W.
Anybody have clarity on the 3rd monitor on the 2nd card for nVidia or will it be the same as with ATI that Patriarch?