Unlike most performance motherboards that by default carry only an x8 / x8 setup when SLI or CrossFire X is used, the ASUS Maximus IV Extreme offers us the NF200 chip to add more PCI-E lanes to the board. Over the last few years we've seen companies implement the chip to boards to help move the default SLI or CrossFire X setup from x8 / x8 which is offered via the Intel chipset, to x16 / x16 via the NF200 chip.
When you move away from a two card setup and into a three card one, boards without the NF200 chip would run x8 / x8 / x4, while with the NF200 we're able to achieve x16 / x8 / x8 which when having so much power on hand, is extremely appreciated.
ASUS do it a little differently, though, and they do it in a way that has confused people. On the Maximus IV Extreme and Extreme-Z, their P67 and Z68 boards, by default they offer x8 / x8 via the Intel chipset. It isn't until you add a third card into the mix that the NF200 chip comes in handy, because in that situation we get a x8 / x16 / x16 setup.
The specifications for multi GPU setups on the Maximus IV Extreme(-Z) boards is 4 x PCIe 2.0 x16 (x16, or dual x8, or x8, x16, x16). So in other words, if you're using one video card, it runs at x16; if you use two or run "dual", it's x8 / x8, and if you run three it's x8 / x16 / x16.
What people asked was, why does ASUS who offers the NF200 chip on these boards opt for a x8 / x8 setup in a dual card situation, when any other company with a dual GPU setup would make use of the NF200 chip and go for a z16 / x16 setup?
Well, ASUS say the way they do it is faster. Huh!?!?! x8 / x8 is slower than x16 / x16, though? - Yes, but because the NF200 chip piggy backs onto the Intel chipset, they say a certain amount of lag is added because another chip is being thrown into the mix.
A good way to look at it is we've got two runners in a 100m race. The x8 / x8 Intel runner is slower overall in straight out speed, but the x16 / x16 NF200 runner has hurdles in his lane and while he can run faster, because he has to jump hurdles (i.e. go through the Intel chip) he's overall actually a little slower.
It makes sense in theory, but before we start to believe that x8 / x8 through the Intel chipset is better than x16 / x16 through the NF200 chip, we need to test it for ourselves. So jump forward to the next page and find out exactly how we go about testing this before we get stuck into the benchmarks to see if there's actually any difference.