Will 2 GPU's not SLI'd run together for gaming?

Dreznon

Honorable
Feb 20, 2016
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I believe that with the app setting of Nvidia's control panel it will run what you tell it to for that app. If that is the case what good is SLI for? It doesn't make sense if you can pair them in the control panel then why SLI? Am I completely wrong? Please get as technical as you can and I will keep up with you. : )

Thanks
 
Solution
So short answer: you might be able run it - but you wont have any performance benefit.

Long answer: your CPU and GFX transfer a hell of a lot of data to and from eachother, to render your display (calculate pixels etc). So now, when you slot in a second card (for explanation purposes you will have a Geforce 960TI slotted already), now you add a second one (provided your MOBO supports SLI).

Now your CPU (depending on which CPU), has the potential to talk to the GPU's over 32 PCI-E lanes, instead of just 16.

Imagine a highway with 8 lanes in each direction - which is stacked with cars bumper to bumper, add 8 more lanes in each direction, and you can fit more cars.

Thats pretty much as simple as it gets.

P.S. to make use of all 32...
So short answer: you might be able run it - but you wont have any performance benefit.

Long answer: your CPU and GFX transfer a hell of a lot of data to and from eachother, to render your display (calculate pixels etc). So now, when you slot in a second card (for explanation purposes you will have a Geforce 960TI slotted already), now you add a second one (provided your MOBO supports SLI).

Now your CPU (depending on which CPU), has the potential to talk to the GPU's over 32 PCI-E lanes, instead of just 16.

Imagine a highway with 8 lanes in each direction - which is stacked with cars bumper to bumper, add 8 more lanes in each direction, and you can fit more cars.

Thats pretty much as simple as it gets.

P.S. to make use of all 32 Lanes, you will have to have a CPU that supports 32 Lanes, Most CPU's only support 24 (so 16 from your first GPU and 8 from your second), which still is a big performance boost, usually you can consider around ~50% extra performance for the second card.

Copy past specs from a I7-2011 CPU:

Details
Core Name Haswell-E
# of Cores 6-Core
# of Threads 12
Operating Frequency 3.5 GHz
Max Turbo Frequency 3.7 GHz
L2 Cache 6 x 256KB
L3 Cache 15MB
PCI Express Revision 3.0
Number of PCI-E Lanes 40


Hope this answers your question.
 
Solution