To SLI or not to SLI...

[dcolodny]

So the setup is this:

CPU: Phenom II x6 1090T @ 3.2Ghz
Motherboard: Asus Crosshair IV Formula
Memory: 8gb
HD1: Samsung 840 Pro 256
HD2: WD 1TB Black (FAEX)
GPU: Sapphire ATI Radeon 58xx (highest single GPU)
PSU: Thermaltake 850w

I'm replacing the 58xx with a 780ti (reference for future watercooling) and in about 9 months am doing a complete rebuild down to the case. (ok, the 840 pro is migrating , but that's it!)

It will look like:

CPU: i7-4790K
Motherboard: EVGA Classified Z97
Memory: 32gb
HD1: Samsung 840 Pro 256 (same drive, will probably upgrade to the 850 pro 512gb at some point)
HD2: WD 4TB Black (FZEX)
GPU1: EVGA reference 780ti
GPU2: EVGA reference 780ti
PSU: Corsair AX1200i (only because I will need a bit more than the AX860i provides and I really like the link feature)

Given that I desire to do 4k gaming (single screen) my question is one of performance of card #3. That particular MB can handle x16/x16 but if I add a third card, the PCI slots drop to 8x/8x/8x. Is 3 cards @ 8x better than 2 cards @ 16x and will I be able to go nuts with the settings @ 4k with just 2 cards?

As you might have guessed, money isn't the primary concern here, but it does factor in by possibly extending (or reducing) the time frame.

 

[ninjacore]

You're looking at very minimal gains comparing 8x to 16x. I wouldn't even consider it, honestly. Any reason you're not considering a 980 instead of the 780ti?

 

[Witchdoctor]

chill, 9 months the landscape will change significantly

Broadwell
980Ti - 20nm ?
M.2 gains
DDR4 possibly near or at 4K speeds
New gen boards

 

[ninjacore]

If you want better graphics performance now, though, I think buying a good single gpu, then adding another later is a good plan.

 

[dcolodny]

I'm in a time crunch, my favorite game just updated their system reqs (effective new years; ya, they're nice with the lead time, they gave 6mo) and I need a new card. From what I had read, the 780ti was slightly better than the 980, but now I'm hearing otherwise, so the 980 is back in the running.

edit: ok, the news that nvidia will be discontinuing the 780ti chip production (if true) kinda makes my choice for me, doesn't it? (at least if I want to sli later and not now)

As to the other boards coming out, I hope they do. It'll drop the price of the Z97 boards. I'm not looking at a truly bleeding edge computer, but a step back from it. Besides, all things are subject to change until the "submit order" button is clicked.

Just to clarify though: 8x vs 16x is irrelevant, it's simply [more cards is better]?