Benchmark scores 980 ti sli???

[HardwareLemon]

Hello everybody i have been wondering for a while now why my scores are low ok so before i explain let me tell you my full system specs.
Cpu - i7 4770 @3.7 ghz
motherboard - gigabyte z87x-d3h
cpu cooler - cooler master hyper 212 evo
Ram - 16gb 1,596 MHz corsair
Gpu 980 ti evga superclocked (x2) 1,101 MHz
Psu - evga supernova 1,300 watt g2 gold
Ssd - Adata sp900 256gb
Hdd (1) Western digital black 1.5 tb (2009 model)
Hdd (2) Western digital blue (2012 model)
Ok so my problem is that if i run 3Dmark firestrike i will get a score of 19,239 and i see other people using only a single 980 ti and they are getting upwards of 16,000 it just doesn't make much sense i know that scaling is not double but thats still pretty close to 2 cards in sli, at least for me it is. Also forgot to mention that i am running 3 1920x1080 (5760x1080) monitors and i have seen benchmarks on youtube of people maxing out GTA V with 2 980 ti's and all advanced graphics turned on without MSAA of course at 4k and getting 60 to 100 fps wheras when i run a benchmark in gta i will get 40 to maybe 60 fps (if im lucky) and i know that 4k requires more power to run so thats what i don't understand, how are they getting more fps than me at a higher resolution with roughly the same boardpartner card's? Also i sometimes have problems in other games like Ark survival evolved keep in mind that i know its still in beta but it seems to be really unoptimized for my cards. My friend has a r9 390 and he can run it at like 60 fps on medium to high settings, when i try that i get 40 to 50 fps. I had the conclusion that this problem could be a bottleneck because my cpu is not the greatest and because it is not a "k" version which means that i cant overclock it beyond the 3.9 ghz turbo boost. My cpu or the i7 4770 also only supports a total of 16 pci-e 3.0 lanes. Sence i have 2 cards installed at the moment and my motherboard only has an x16, x8 avalible for nvidia gpu's so naturally it and the cpu will slow the speed to the first two pci-e lanes to 8x to compensate for only having 16 max lanes for the cpu. I am still considering this as a possible problem however it is not much of a performance drop from 16x to 8x so idk. so what do you guys think, could it be a cpu bottleneck or is it drivers, i also have updated my drivers. Anyways if anyone has any advice or recommendations feel free to respond.
Sorry in advance for any grammatical errors as i am writing this at like 1 in the morning and i don't have much time to check it over

all answers will be greatly apreciated

-Thanks

 

[Starcruiser]

Your motherboard is the likely culprit here. When you have 2 cards in SLI the motherboard reduces both PCIe slots to x8 speed. A better motherboard (mostly z97 chipsets) will be able to run 2 slots with one or both at x16.
Also please forgive my not wanting to read such a large solid block of text. It's difficult to read like that.

 

[SinxarKnights]

Firestrike Search Results for 4770 + 980ti x 2

The very top score for this config is 20463. You are right on the money pretty much.

 

[JWoody]

Even limiting a slot to 8x shouldnt cause a performance decrease at all, considering a PCI-E 1.0 x16 slot would even have enough bandwith for a Titan X and a 8x 3.0 or 2.0 slot would have more bandwith than PCI-E 1.0 @ x16, is possibly one slot jumping down to 4x or less?

 

[Dragos Manea]

1st of all 3d mark score is not only about graphics card, it si about cpu too so the total score will increase with a few k of points but graphics score will almost double, to double the total score you must double the cpu power, ram speed and graphics.
Here si with sli http://www.3dmark.com/fs/5829612 and here is single 980 ti http://www.3dmark.com/fs/7228718. As you can see at graphics score single si 21k and sli is 36k (almost double). As you said scaling is not eprfect but it is close.