Click here for a 3000x2500 high-res shot of the board (3 MB download), the backside is here.
Near one of the edges of the KN1 SLI Extreme, ECS attached a nice "ECS Extreme" badge which comes with a protective foil on it, so it will be scratch free.
The CPU socket area is well cleaned up, there is plenty of space even for bigger coolers.
While the big neon-colored exhaust fan takes quite some space away, ECS has managed to put the most important connectors there: PS/2 Keyboard, PS/2 Mouse, one Serial Port, SPDIF, four USB Ports, Dual Ethernet, Audio.
The motherboard's memory slots have been color coded for easy dual-channel configuration. To run your memory in dual-channel mode you have to put the modules into slots of the same color. I find the placement a bit uncommon, usually it is, that you have one empty slot between the modules when you run dual-channel which helps the memory temperatures a little bit.
The 24-pin ATX power connector is very conveniently placed, the ATX12V connector could be placed in a better location. A third 5.25" power connector is available to increase the power supplied to the motherboard. If you are going to use a 24-pin power supply you have to remove the yellow "24 Pin" sticker from the connector.
Six SATA-II capable ports are available on the ECS KN1 SLI Extreme. They are arranged in two groups, the group of four connectors is the ports of the nForce4 chipsets, the other two are from the Silicon Image Add-On chip.
Two ATA-133 ports are located near the ATX Power connector, the green and the white port are for IDE, the white port below the ATX Power connector is the floppy connector.
The color scheme of the Reset/Power/LED connectors helps finding the right pins when installing the board the first time.
Most nForce4 motherboards need a small SLI switch card to change the PCI-Express slots into a configuration suitable for running SLI. ECS does not need this, the detection and switch is automatically once two suitable cards are installed.
If you use a two-slot video card in the top slot, you will lose access to the only PCI-E x1 port. A better solution would have been to put that port above the top slot, so it remains accessible.
If you want to use the SLI Feature of your NVIDIA VGA cards, you will have to link them together by using the included SLI bridge. New drivers have added a way to run SLI without the bridge, but this results in a performance hit.