The back panel for this motherboard is fairly standard for a high-end platform of this nature, mixing legacy and modern I/O ports to meet virtually everyone's needs. The board is still equipped with PS/2, serial, and parallel ports, while also sporting a 6-pin Firewire 400 connector and four USB 2.0 ports. The board also comes with expansion cards which allow for two more USB 2.0 ports (another set of USB 2.0 ports are available via color-coded pins on the motherboard) and two more Firewire 400 ports to be added to the rear of the chassis. In total, this board supports ten USB 2.0 devices and three Firewire 400 devices.
The motherboard also sports dual Ethernet ports, both supporting Gigabit Ethernet transfer speeds. The GigE port to the left is powered by a PCI Express x1-based Marvell 88E8053 controller, while the port on the right is a native nVidia Gigabit Ethernet port. As always, the native nVidia port supports such features as TCP offload and an integrated Firewall, although the real-world performance benefits of both have been questionable at best.
As you can see above, a good portion of the motherboard's I/O panel is dedicated to the onboard audio abilities of the motherboard. The panel supports eight channel analog audio output, along with both optical (right) and coaxial (center) S/PDIF digital outputs. These connectors aren't too unusual for a high-end platform such as this, but what they are connected to on the motherboard /is/ quite unusual, as this ends up being truly one of the stand-out features of this motherboard.
Instead of connecting to a software-based AC'97 or HD audio CODEC, MSI's design allows these ports to connect directly to a Creative Labs hardware audio chip. MSI has ripped the soul of an Audigy SE audio card, taking the hardware audio controller and DAC chips and implanting them directly on the motherboard. This means that the onboard audio of the MSI K8N Diamond Plus is a hardware audio solution, as the audio processor can process audio streams without reliance on the system's CPU. This is the first onboard audio solution which should be up to par with what gamers have been demanding all along. A true, high-quality hardware audio processor which won't slow down their games when processing 3D positional audio. This is a nice addition, as it allows you to ditch expensive Creative add-in audio cards for something that's more compact and (surprisingly) more flexible. Creative's add-in cards never provide optical/coaxial digital outputs by default, and none support the pin-set for connecting the front panel audio ports of your chassis. MSI's implementation does just that.
However, it's a bit confusing to us as to what this chip actually is. The labeling on the chip calls it the Creative CA0106-DAT, which is sold both as a SoundBlaster Live! 24-bit controller, but is also the chip of choice on some Creative Audigy LS/SE (value) boards. Whatever the name is, this hardware controller supports 7.1 audio, supports 24-bit / 96 KHz high-quality digital audio, and supports EAX Advanced HD positioning technologies. Creative calls this chip an "Audigy SE", whereas installing the card in Windows XP x64 Edition called the chip a Sound Blaster Live! 24-bit. In any case, we tested this audio processor and found audio quality to be excellent. In fact, after using a Creative X-Fi card and moving back to a this onboard Creative APU, we heard very little difference between the two.
MSI is also selling variants of this motherboard as a "Hi-Fi" version which includes a audio vacuum tube which is installed in a 5.25" drive bay, but connects to the same Creative onboard controller chip. Most who have tested this vacuum tube solution claim no difference in audio quality, although the tube "looks neat" installed in your drive bay. MSI has largely backed off of advertising the Hi-Fi solution, and it looks like most all of the boards on the market today are the standard solution without the tube.