ASUS RoG Maximus III Extreme LGA 1156 Motherboard Preview

PCI-E Layout and PLX Chip Functionality

As with most higher-end motherboards, the ASUS Maximus III Extreme supports a total of 40 of PCI-E lanes spread over five slots through the use of an nForce 200 chipset. The slots themselves are laid out in such a way that up to four can be populated with dual slot GPUs without any issues. However, if you want to use five cards, you will need to use one which has a single slot heatsink design.


In the chart above, you can see how the slots themselves switch between x16 mode and x8 when multiple GPUs are installed. However, even with the nForce 200 chipset, all of the slots default to x8 mode when more than three cards are installed.


The PLX chip which is installed on the Maximus is used to allow PCI-E lanes to be used for the SATA 6GB/s and USB 3.0 ports. This isn’t as good as a native solution due to latency but it is the only way to go about it until Intel adds this support to their lineup.