EQS A72K9-CF Layout
EQS stick to the basic Halibut reference design created by the ATI mainboard team pretty closely, but with a few changes here and there. ATX12V power sits directly next to the power regulation hardware it serves before that power is passed to the nearby CPU socket. The socket sits high up on the board with the quartet of colour coded memory slots right next door. The colours are chosen to indicate how to enable dual-channel memory operation. HEXUS enabled that throughout our testing by using the pair of blue slots nearest the processor.
Past those sockets you've got the floppy port and, curiously, an old 20-pin ATX main power connector rather than the very common 24-pin type (for extra +12V inputs) that's been in use on modern mainboards for quite some time now.
The northbridge is very close to the CPU socket, topped by a passively cooled heatsink that's been popular on many a mainboard in recent times. EQS place the secondary PCI Express 16X connector (note that the lower PEG16X slot is primary on this board which is required knowledge for Crossfire) very close to the northbridge which might cause problems for graphics boards that have oversized cooling hardware on the rear.
The side effect of placing that slot so close to the northbridge and that high up the board is that, alongside the PCI Express 1X expansion slots, EQS can supply the board with three PCI Coventional slots. EQS place the southbridge with black passive cooler in the bottom right corner of the board as expected, the devices, ports and slots that connect to that all-in-one ASIC nearby.
You've got the pair of IDE ports along the right hand board edge, SATA ports in a row just underneath (although I'd have pushed them even further to the right hand edge of the mainboard if I were the A72K9-CF designer) and PCI-riding VIA V76307 FireWire 400 controller right next door.
A Realtek RTL8100C Fast Ethernet (10/100) network chip, also riding the PCI bus, can be found next to the 2nd PCI Express 1X slot. EQS place GigE-on-PCIe Marvell networking and Realtek ALC880 HD Audio chips on the left hand edge of the board. That's about it, too.
My only layout quibble, with headers for things like FireWire and USB2.0 (8 ports supported) in the right place give or take, is that the high placement of the topmost PCI Express 16X slot means that you'll need to remove the graphics card to adjust your memory configuration. No huge deal, but worth mentioning.
The backplane space is occupied by PS/2 ports for keyboard and mouse, parallel port (why oh why?), blanking plate for where the VGA output would be on a different version of this mainboard, USB and Ethernet ports and the 8-channel ALC880's jack compliment for getting sounds into and out of that chip.