There’s been some discussion among Tom’s Hardware staff about whether the CrossFireX performance gains seen by adding the nForce 200 bridge to the P55 platform were simply a matter of accessing the processor's faster PCIe 2.0 lanes. Beyond the potential division of the CPU’s 80 Gb/s PCIe bandwidth across three cards, possible improvements include the ability of the cards to communicate with each other at up to 40 Gb/s (at x8 mode for three cards) and, more importantly, the likelihood that all of the cards connected to the NF200 are receiving the same data from the CPU (the performance equivalent of 32-lanes from the processor's 16). Surely the NF200 could also be used to provide the X58 chipset with enough additional lanes to support three graphics cards with the full set of 16 pathways, but would those extra lanes provide the 4% performance difference we noticed between x8 and x16 slots in our PCIe Scaling Analysis?
We needed to know whether or not the nForce 200 bridge’s extra lanes could add any "punch" compared to our X58 motherboard’s chipset-supported x16/x8/x8 configuration, and we also wanted to see how much performance loss would be incurred by using a less-expensive, x16/x16/x4 mode X58 motherboard. The X58+NF200 configuration came via MSI’s Eclipse Plus with its only BIOS release (V1.1), while the Asus P6T (BIOS 0801) represents the reduced-cost X58 option.
Our Far Cry 2 benchmark set was picked as the “most typical indicator” of gaming performance.
The NF200-equipped MSI Eclipse Plus beats the X58 native solution at medium resolutions, but the performance becomes identical at 2560x1600. The highest resolution is also where Asus’ x16/x16/x4 configuration falls behind, but not by enough to discourage most buyers from looking towards this less expensive motherboard as a potential value leader.
The NF200 advantage for X58 motherboards disappeared when we enabled AA. Because it’s cheaper than all but the EVGA P55 SLI motherboard, Asus’ P6T continues its hold on value.
- When Does 16/2=32?
- Test Settings And Boards
- Benchmark Results: Crysis
- Benchmark Results: Far Cry 2
- Benchmark Results: Tom Clancy’s H.A.W.X.
- Benchmark Results: S.T.A.L.K.E.R. Clear Sky
- Benchmark Results: World In Conflict
- Benchmark Results: 3DMark Vantage
- Performance Summary
- But Can NF200 Help X58, Too?
- P55 Triple-GPU CrossFireX, Fixed?