You're getting two reviews for the price of one here as the Sapphire PC-AM2RD790 is identical to the DFI LAN Party UT 790FX-M2R. We're told that this Phenom motherboard is a joint venture between Sapphire and DFI but to my eye it looks like a DFI right down to the LAN Party logo that is printed above the bottom graphics slot. There is a small amount of ambiguity as the board doesn't carry either DFI or Sapphire logos but the style and design shriek DFI at every turn.
It's the cooling system that stands out as it doesn't quite follow the usual form. There are three passive coolers that are linked by heatpipes with one on the Southbridge and one on the Northbridge but the third cooler doesn't sit on the power regulation hardware. Instead this U-shaped cooler is located in the I/O panel between the PS/2 ports and two of the USB ports so the power regulation chips are left bare. Unusually the power system has seven phases with six phases for the CPU and one phase dedicated to the Northbridge. If you're an overclocker you might want to sit up and pay a little more attention as this feature is clearly aimed at you.
Moving the third cooler away from the CPU socket means that there is plenty of space that looks as though it is tailor-made for a chunky CPU cooler but I'm not so sure this is the case. The first RAM slot is quite close to the CPU in the usual AMD style so the CPU socket is wide open on three sides and overshadowed on the fourth. You'll have no trouble if you watercool the Sapphire but that seems like an extreme approach for cooling a processor that is notoriously difficult to overclock and thus seldom that toasty.
I haven't quite finished with the chipset cooling system. The passive cooler on the Southbridge has been formed from an aluminium extrusion and looks as though it might be part of a shelving system. It is quite long and also very low in profile which is a good thing as it comfortably clears the multiple graphics slots but the Northbridge cooler to which it is linked is tiny and would be dwarfed by a decent-sized postage stamp. This isn't necessarily a problem as the heat from these two coolers can be shunted up the heatpipe to the third cooler which sits behind a vented I/O shield. The snag is that the cooler is passive and is a fair distance from the CPU cooler so there is no airflow to keep it cool. As a result it gets rather toasty and we had to rig up a case fan during testing to prevent the system locking when it was under load.
The three coolers are mounted to the motherboard with screws and nuts which is a detail that should appeal to the enthusiast. Despite that we can't shake the nagging feeling that this doesn't change the fundamental point that a conventional layout might have been a smart move.
You might think that we've done the cooling system to death but the layout has a knock-on effect to the rest of the board. With half of the I/O panel occupied by a passive cooler and a pair of legacy PS/2 ports at one end there is only room for six USB 2.0 ports, one Firewire port and dual Gigabit LAN. All of the audio connections have been moved to a riser card which also carries the Realtek AC888T chip but Sapphire hasn't gone the whole hog as the riser doesn't have a PCI or PCI Express interface but instead it connects to the board with a Bernstein audio cable. That may sound mysterious and Germanic but an inspection reveals it to be a short ribbon cable.