@Alen Pecanin
Hi Alen,
your points:
i) delta 680gtx sli to single card
ii) delta 680gtx to 970
iii) delta 970 sli to 680gtx sli
iv) sli probs & hassle
i) delta 680gtx sli to single card
680 sli: ~63% improvement with second card
http://www.guru3d.com/articles_pages/geforce_gtx_680_sli_review,12.html
Metro 2033: 69% improvement
Crysis 2: 44%
Battlefield 3: 77%
ii) delta 680gtx to 970
estimate: 36%
proof:
http://www.computerbase.de/2013-06/nvidia-geforce-gtx-760-test/4/
click on "12 weitere Elemente" in first benchmark section: "Leistung ohne AA/AF", hover over gpu name:
gtx 760=100%
(gtx)770=123%
compared to:
http://www.computerbase.de/2014-09/...vidia/6/#diagramm-rating-1920-1080-4xaa-16xaf
760=100%
770=123%
-> both tables comparable
from 1st table:
680=100%
770=105%
from 2nd table:
770=100%
970=131%
comparison:
680=100%
970=136% (with 31% delta from 770 + 5% delta from 680)
measurement:
improvement 680vs970 per resolution
4K=~60%
1080p=
~42%
http://www.extremetech.com/computing/190463-nvidia-maxwell-gtx-980-and-gtx-970-review/2
Bioshock Infinite:
4K=64%
1080P=40%
Metro Last Light
4K =56%
1080p=45%
Note that the 970 was overclocked by Zotac:
standard:
[in Mhz]
chip: 1050
memory: 1178
Zotac:
chip: 1102
memory: 1241
=> the 970 performs much better the higher the resolution
The 970 also has relative low power consumption, is more efficient and has useful features like automatic downsampling which noticeably improves the video quality. The 970 also features 4GB of Vram, 2GB more than the 680 - more Vram is used by higher resolutions, the more Vram is available, the more it will be used.
More info:
http://www.guru3d.com/articles_pages/nvidia_geforce_gtx_970_and_980_reference_review,14.html
http://www.overclock.net/t/502403/graphics-card-ranking
gtx680 2GB = 24th place
gtx970 = 9th place
Partnercards:
Palit:
http://www.guru3d.com/articles-pages/palit-geforce-gtx-970-jetstream-review,1.html
ASUS:
http://www.guru3d.com/articles-pages/asus-geforce-gtx-970-strix-review,1.html
Gigabyte G1:
http://www.guru3d.com/articles_pages/gigabyte_geforce_gtx_970_g1_gaming_review,1.html
MSI:
http://www.guru3d.com/articles-pages/msi-geforce-gtx-970-gaming-review,1.html
iii) delta 970 sli to 680gtx sli
970sli:
~71% improvement with second card
http://www.guru3d.com/articles_pages/geforce_gtx_970_sli_review,18.html
[in %]
Bioshock Infinite:
1920x1200 = 69
2560x1440 = 78
4K = 69
mean: 72%
Crysis 3:
1920x1200 = 75
2560x1440 = 80
4K = 55
mean: 70%
=> 970 sli scales better than 680 sli, mainly because of more efficient chip structure and more Vram
680sli vs 970 sli:
3DMark 11 P score:
680 sli: 14463 (vs 9458 single card -> 53% improvement)
970 sli: 20426 (vs 13548 single card -> 51% improvement)
=> a single 970 is not much slower than two 680
Note that 3DMark is a synthetic benchmark and doesn't necessarily represent the performance of specific hardware in stand alone games
iv) sli probs & hassle
Not many from what I've read so far. The new-ish drivers do a good job with scaling.
Having said that, this SLI / Crossfire thing is pure marketing and total bs in my humble opinion.
For it to be a viable alternative over buying a single card of a new gpu generation, SLI should scale 100%, which is only very seldom achieved, SLI/Xfire increases power consumption, heat generation (heat is the lowest form of energy and a waste product in this system) and noise. All of whom you don't want running a decent PC.
Concluding:
Sell your 680 and buy a 970.