The Epox 9NPA+ SLI has quite a few integrated options, but should you want to upgrade there are three legacy 32-bit PCI slots, one PCI Express x1 slot as well the two PCI Express x16 for graphics cards. When the system is running with one videocard, the second PCI Express x16 slot operates as an open PCI Express x1 slot.

One really neat feature that case modders will love is the row of activity LEDs to the right of the four DDR DIMMs. The little LEDs act as a memory activity indicator, much like the ones found on Crucial's Ballistix and Corsair's PRO line of memory. There are a total of eight LEDs which represent DRAM modules one to eight. The NF4 SLI is not ECC compatible so that is why there is no 9th LED.

Dual graphics on the EP-9NPA+ SLI are implemented via a physical switch card; it is not the most efficient method but works quite well. When running two PCI Express x16 videocards in SLI mode the user will need to flip the card into the SLI position, which just takes a moment or two. Epox has always had well written manuals as far back as I can remember and the EP-9NPA+ SLI is no different. The motherboard is very well laid out but if you have any problems (like in the BIOS), the manual will be able to guide you for sure.

The Port 80 diagnostics card is probably the most useful tool for any overclocker/tweaker as it displays a two digit code which tells you exactly where a hardware problem lies. This standard has been around for over twenty years and the nice thing is, no matter which motherboard/system, the Port 80 codes remain the same. The codes on the two-digit alpha-numeric LED display help troubleshooting when problems crop up by identifying what exactly is wrong with the system. The corresponding codes in the manual quickly point the user in the right direction to solve the issue.

From 'C1' or 'C3' errors that indicate memory related problems to '26' (the most common for overclockers) which means the system has overclocked too high, to 'FF' which indicates no hardware error; once you learn the codes, you will know the values no matter which motherboard you use. Considering how long this standard has been around, motherboard manufacturers should make this feature standard and get rid of the proprietary diagnostics LED used with other brands. So far Epox is only manufacturer that makes the Port 80 diagnostics card standard equipment on its motherboards.

Epox uses a GeForce3 style cooler on the NF4 SLI chipset and overall it does a decent job. During testing the heatsink did get quite toasty, however the system remained 100% stable and the little cooler was definitely up to our overclocking challenge as you will see shortly. ;-)

The board uses a 24 pin ATX power connector, but this is backwards compatible with 20 pin ATX power supplies as long as it has enough power to go around.

Those of you with longer videocards might want to take notice that it might interfere with the NF4 Serial ATA II ports. When running with two GeForce 7800 GTX cards in SLI, the bottom card would slightly get in the way of the first Serial ATA channel.