The highlight of this product is of course the presence of seven PCI Express x16 slots. The Classified SR-2 supports both SLI and CrossFireX modes, and it comes with three SLI bridges – one for installing two video cards, one for installing three video cards, and one for installing four video cards – but with no CrossFireX bridges.

The north bridge of the Intel 5520 chipset provides 36 PCI Express x1 lanes, while the south bridge (ICH10R) provides six more lanes. This is the same configuration used by the Intel X58 chipset. The EVGA Classified SR-2 also comes with two NVIDIA NF200 bridge chips.

The first, the third and the fifth slots are labeled as “16x/8x.” The second, the fourth and the sixth slots always work at 8x. And the last slot is labeled as x16. According to EVGA when the first, the third, the fifth and the seventh slots are used, they all work at x16. Usually motherboards that support four-way SLI or CrossFireX configurations will have at least some of their slots working at lower speed grades when four video cards are installed, which doesn’t happen with this product. When more than four video cards are installed, then all slots work at x8. We had to ask EVGA for this information, as it is not written anywhere.

This motherboard allows you to install up to four dual-slot video cards. If a fourth dual-slot video card is used, it will block the power, reset and clear CMOS buttons, and you will need a case with 10 expansion slots.

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Figure 2: Slots.

As you can see, this motherboard doesn’t have PCI Express x1 or standard PCI slots. The absence of x1 slots isn’t a problem, as PCI Express technology allows you to install x1 expansion cards on any PCI Express slot (i.e., they will work when installed on x16, x8, x4 or x1 slots).