SLI not working effectively in a lot of games?

[xtobymc]

Today I received two new GTX 970's for my PC and so this is the first time experiencing SLI configuration. The entire installation was fine and I had no issues, Nvidia control panel clearly states that SLI is being used across the cards.

The problem is that most of the games I've tested have barely utilised the SLI. I bought two cards for the purpose of increasing frame rates at 1440p, but the fps remains at a value you'd associate with a single GPU. For example, it'll be 80fps when it should be around 140fps with SLI (my monitor is overclocked to 110Hz by the way).

I used Nvidia Inspector whilst playing a few games to monitor both cards, and it seems that the GPU loads aren't right. In ArcheAge for example, both cards were at ~50% load the entire time and my fps didn't improve compared to when I used to use a single GPU. In The Forest, only one card was at 100% load, whist the other was at around 1%. It's the same pattern across a lot of my games, except big titles like Battlefield 4 with a lot of optimisation.

Is there something I'm missing?

 

[thekyle64]

not all games are optimized for sli

 

[bistwo]

Only certain games support SLI. Another problem many people don't see is that many chipsets only have one fully capable PCI-E x16 lane, and the others, although they are a full length slot, only operate at x8 speeds.

 

[thekyle64]

what cpu and mother board do you have

 

[xtobymc]

what cpu and mother board do you have

i5 3570k at 3.7GHz and an Asrock Z77 Extreme 4 motherboard which definitely has two x16 PCI-E slots

 

[Eximo]

Only certain games support SLI. Another problem many people don't see is that many chipsets only have one fully capable PCI-E x16 lane, and the others, although they are a full length slot, only operate at x8 speeds.

PCIe 3.0 or even 2.0 at 8x is more then enough for any video card on the market.

Most of the big games have SLI profiles, as you have noticed.

You also have to take into account the rest of the system. You may be facing CPU bottlenecks in some of these titles. Some game engines will limit the FPS output, or have V-sync forced on. Just have to look at each individual game for SLI support.