2x GTX 660 Ti (SLI) + GTX 560 for PhysX or a single GTX 780?

I'd like to ask what makes more sense for a GPU upgrade i'm planning to do next year.

Right now, i'm running an ASUS GTX 660 Ti and a GIGABYTE GTX 560 dedicated to PhysX.

I have a limited budget, so i can do following: either buy a single GTX 780 (and there will be no money left), or buy another GTX 660 Ti (i know they have to be exactly same), buy a new mobo - that would be ASUS Sabertooth 990FX R2.0, and a 1000W PSU. And again use the GTX 560 for PhysX.

So my question is, what makes more sense? Also, what comes in to my mind; is it even possible to have this SLI combination - 2x GTX 660 Ti + 1 GTX 560 for PhysX? Will it work if i choose this way?

I would sell the 560, to me there's no reason having a card for the 1 good game a year that uses physx.

Why do you want to replace the 660ti? It's a good card.

I would go with the 660ti in sli without a dedicated 560 for physx it would be a tad better than a 780 at cost much less.

Thanks for input guys, so the 660 Ti in SLI is probably my dfeinitive choice for now if it really outperforms the GTX 780, there is no question to be asked anymore. I would ditch the GTX 560 and PROBABLY not need to buy a new motherboard and PSU, which leads to new set of questions:

- Will my current 750W PSU handle two 660 Ti's ? It's rated 80PLUS BRONZE and has 88% effectivness if that helps. I'm not that stupid when it comes to hardware, i build (and overclocked) that PC i have in my sig myself, it's just i'm getting lost in this exact case - SLI wattage and SLI'ed GPU's versus a single GPU... :)

- Next thing is my motherboard. It has 2x PCI-E 2.0 16x, but one runs at 16x (where i put my 660 Ti) and the second one is only 4x if i understood correctly the specs. Here's a link to my mobo specs if you wanna look: ASUS M5A97 R2.0 specifications . Should i rather get that ASUS Sabertooth 990FX R2.0 just to be ''futureproofed'' or will my current one do it?

Please help me, i'm getting kinda confused...

I'd go with the single 780. Less hassle, always works, better performance.

dedicated GPU for physX? Who does that any more? You have a 660ti, you don't need a a dedi GPu for physX. This is an easy question, with an easy answer: GTX 780.

What 660Ti do you have? If it's the 2gb version, get the GTX 780. You're going to want to extra vram. If it's the 3gb version, the SLI setup looks better, but I would still go with the 780. A single card setup is much easier to deal with than SLI.

That board doesn't support SLI. SLI requires PCIe x8 at least to work.

The Sabertooth 990FX definitely does support SLI... OR did you miss the part about him buying a new motherboard?

Taken from this post here

I assume he has a board that does not support SLI. The 990FX may very well support SLI, but his current one does not.

Wait.. what what? Why do you need a 1000w PSU....

Well, i have dedicated PhysX GPU just because i can, lol. I had a GTX 560 before, then upgraded to 660 Ti, and since i had no use for that 560, i put it in the second PCIe slot for PhysX. If i rememeber correctly, Batman: Arkham City recommends dedicated GTX 560 for PhysX when you want to run PhysX on ''Ultra'', so... There might be something to it, don't you think?

About your 1000W PSU question - that was if i was running 2x 660 Ti in SLI + 560 for PhysX. If i'd go with 2x660 Ti, then i would have to buy a new mobo, which would be supporting Quad SLI, and JUST BECAUSE I CAN, i would most likely put the 560 for PhysX and my current 750W PSU couldn't handle it no matter what. So i would buy a 1000W PSU, just to be ''futureproofed'' because each new NVIDIA GPU is more and more power hungry...

@Toxic-Seahorse

I have ASUS GTX660 TI-DC2O-2GD5 . So a 2GB model. I always thought that in SLI the cards share VRAM, so basically that would mean 2+2 = 4GB of VRAM... Was VERY wrong i guess. Mind you that my TV (i use a LED TV as a monitor) has max. resolution of 1920x1080 and so far i play ALL games at that resolution. And want to keep it that way. Exceptions are stereoscopic 3D games like Crysis 3, Injustice, Assetto Corsa, Street Fighter X Tekken etc... but i'm getting a bit offtopic here...:)

A little important note guys, if you didn't notice it in my sig: i have an AMD FX8320, OC'ed to 4.4 GHz, but i'm worried (probably rightfully) it might badly bottleneck the 780 GTX, or am i wrong? I have a watercooler for CPU, so i think i could push the OC level even higher with a proper motherboard (i made VERY bad choice with my current one), but still, will be the bottleneck THAT big?

Oh, I see what you were replying to now. I thought you were just replying to the OP. My mistake.

As for the bottleneck, your CPU shouldn't bottleneck a 780 as your CPU should be able to max out every game. Sure, your CPU might hold you back from getting some even higher framerates, but it shouldn't matter in the grand scheme of things. Plus, you may get a new CPU in the future and can still use the card.. If you can afford the best card, get the best card. That's my motto.

What resolution are you playing at?

1080p in general and don't go lower than that, because on my 55" screen it would be a blurry mess.. When i play in stereoscopic 3D, then it's 720p - that makes it 720p for each eye, so it's technically like 2560x1440. But i use it rarely. Only for games that support it really well. Oh, and by the way, 720p in 3D with applied at least 4xAA and 16xAF is NOT blurry as some might think, it looks amazing.

On i sidenote, i decided to buy that ASUS Sabertooth 990FX mobo and go with the 660 Ti SLI setup. Will sell the 560 to my friend, who only got a terrible GTS 450... And that's it.
If you ask WHY i decided this, it's because it will save me money and the performance boost will be still great. You see, i'm from Czech Republic and non-reference ASUS GTX 780 over here costs 12500 CZK right now. While i can get new mobo (3700 CZK) + ASUS GTX 660 Ti (5500 CZK) for 9200 CZK. It's a great difference. In US dollars, to make it easier for you guys, i'd probably save about 170 bucks...

Cool, show us the before and after benchmarks :)

I have a Gigabyte GTX 660 Ti 2 WAY SLi config and a 750W PSU, which is more than enough, and I can say that games nearly double their performance. I was tempted to upgrade to a single powerful GPU solution but I chose the sli configuration due to a very good airflow and cable management and my powerful PSU. Never going over 75C with the cards while gaming and a smooth and outstanding performance on max quality on the latest most demanding games such as Battlefield 4, Call of Duty Ghosts, Crysis 3. SLi has become a reliable configuration!

A single card is always best.