Conclusion

So, this test session proves that the Nvidia nForce4 SLI X16 chipset is the highest-performance and well-balanced solution for multi-GPU systems with Nvidia GeForce 7 graphics cards.

Using correct BIOS settings and the new version of the nForce4 SLI X16 driver, we retested the new Nvidia SLI platform that features two architecturally complete PCI Express x16 slots. We had earlier tested the same platform to find that the new chipset had no advantage in real-life gaming applications, but this turned out to be the result of some defects and errors in the ASUS A8N32-SLI Deluxe mainboard and Nvidia’s technical documentation.

As we already said at the beginning of the review, the current revision of the A8N32-SLI Deluxe automatically drops the frequency multiplier of the HyperTransport link between the chipset’s Bridges from the default 5X to 2X when you update the BIOS or reset the BIOS settings by clearing the CMOS chip. As a result, the bus frequency goes down to 400MHz (200MHz x 2) from the nominal 1000MHz (200MHz x 5) and the bandwidth drops in more than two times, from 8GB/s to 3.2GB/s. Of course, this affects the performance of the mainboard, especially where the bus bandwidth is a critical performance-related factor like in data compression applications or in SLI mode with enabled SLI AA.

Using the correct BIOS settings and the version 6.85 nForce4 SLI X16 driver, we saw the ASUS A8N32-SLI Deluxe perform as fast as the ASUS A8N-SLI Premium and sometimes even produce a nice performance boost in extreme full-screen antialiasing modes. We want to note that it was not only the correct setting of the BIOS option, but also the new version of the chipset driver, which obviously improves interaction with the memory controller, have had such a positive effect on the performance of the mainboard.

It is natural that we’ve observed the biggest performance gain in games that draw large-scale scenes with high-resolution textures. Particularly, such games as The Chronicles of Riddick, Far Cry, Half-Life 2, and especially Unreal Tournament 2004 reacted readily at the increase in the number of PCI Express lanes. The performance gain relative to the nForce4 SLI varied from 2% to 10%, and up to 30% in Unreal Tournament 2004. In other words, the new chipset from Nvidia has really proved it can be the foundation of the most efficient multi-GPU platform for Nvidia’s GeForce series graphics cards.

As for the news from the opposite camp, Nvidia’s archrival, the Canadian ATI Technologies, is expected to announce its Radeon Xpress 3200 very soon. This chipset may become a serious opponent to the multi-GPU SLI platform and, as usual, you will certainly see it tested on our site!