Dual monitor - which gpu?!

[Greeny93]

Currently have -

i7 3820 @ stock 3.6
16gb 1600mhz ram
GTX 580 1.5gb
With a 750w psu

Using a 23" 1080 monitor.

Looking to upgrade to another monitor, 23/23" 120hz.
Figured i'd have to upgrade gpu for the new monitor...

Planning on either sli'ing the 580, or selling it & getting a pair of 660's ( very similar price atm so seems a no-brainer )

Would the sli 580/660's be enough for most games to be run on ultra/fairly high at 120hz?
And would adding a secondary 23" monitor just for interenet browsing etc affect the main monitor's fps by much while gaming on the 120hz?

Very last question - 750w wont cut it, 1000/1250?

Thanks a lot.

edit - mainly use the monitor for bf3/ upcoming games & CAD.

 

[Rusty0611]

You can run different resolutions / refresh rates in extended desktop mode.

You don't need more than 750W for SLI 6** cards providing it's a good quality PSU.

Could you just define what you mean by powerful enough to run 120 Hz? You can technically run 120 Hz off any graphics card with an output for it but I assume you mean close to 120 FPS? The difference in smoothness doesn't come from running close to 120 FPS although of course this does help. The difference in smoothness comes from the monitor side.

 

[Orcvader]

Your 580 is enough isn't it? Unless you want to achieve 120+ fps to make full use of the 120hz. And an extra monitor won't affect framerates at all.

 

[Greeny93]

Thanks for the replies,
Sorry the 120hz monitor would be for 3D gaming.
Meaning i'd effectively need 120fps ? ( 2x 60fps? )

The PSU is alright, 80+ effiency rating... but single 660's max at 300w~ max load? 2x is going to be 500w+ surely? +hdd's+cpu+fans etc, will surely go beyond 750w? :/

 

[Orcvader]

Thanks for the replies,
Sorry the 120hz monitor would be for 3D gaming.
Meaning i'd effectively need 120fps ? ( 2x 60fps? )

The PSU is alright, 80+ effiency rating... but single 660's max at 300w~ max load? 2x is going to be 500w+ surely? +hdd's+cpu+fans etc, will surely go beyond 750w? :/

Just try it with the 580 alone and see if it's fine with running 3D, the 580 is still a pretty powerful card.

And that's just silly about needing 750w+: http://www.anandtech.com/show/6159/the-geforce-gtx-660-ti-review/18

Including the other components, max power consumption is just over 300w, adding an extra 660 Ti would bring it close to ~450w (The 660 Ti is rated for 150w). I would get a 650w+ PSU though to have some headroom.

 

[Rusty0611]

You don't need 120 FPS to run a 120 Hz monitor.