SLI and CrossFireX tandems always show good performance scalability in Futuremark benchmarks, especially at high settings. The GeForce GTX 660 Ti is no exception, the second card adding 50 to 82% to the single card’s performance in 2-way SLI mode. The performance growth is smaller in 3-way SLI mode. It only amounts to 14-32% compared to the 2-way SLI configuration. The three GeForce GTX 660 Ti cards are a mere 2-8% ahead of the dual-processor GeForce GTX 690 which costs less. So, 3DMark Vantage doesn’t think much of the GeForce GTX 660 Ti when it comes to multi-GPU configurations. What about 3DMark 2011?
The newer and heavier version of 3DMark is more favorable towards the 2- and 3-way GeForce GTX 660 Ti configurations, reporting that they increase the single card’s performance by 65 to 86% and an additional 27 to 44%. Unfortunately, the 3-way SLI configuration is still not fast enough to justify its cost, even though it enjoys a larger advantage over the GeForce GTX 690 than in 3DMark Vantage.
Unigine Heaven Demo
The 2-way SLI has a large advantage of 84 to 94% over the single card in Unigine Heaven but the 3-way SLI is less efficient, adding 21-45% to the performance of the 2-way GeForce GTX 660 Ti and being but slightly faster than the single GeForce GTX 690.
S.T.A.L.K.E.R.: Call of Pripyat
This game produces interesting results. Where not limited by the platform, the SLI configurations can substantially boost both the average and bottom frame rate. The latter is rather an exception, as we’ll see in the next game.
Metro 2033: The Last Refuge
The SLI configurations improve the average frame rate in this game well enough. Even the 3-way SLI adds 44 to 53% to performance. The bottom frame rate is a different story, though. It even lowers as we add more GeForce GTX 660 Ti cards into our system.