EPoX 7KXA KX133 Slot-A ATX

The Good

Click to Enlarge

The 7KXA is the first available KX133 motherboard on the market, which by itself will sell quite a few of these boards. VIA worked quite a bit with their partners to make sure that designs based on the KX133 were as close to perfection as possible; it just so happened that EPoX's boards made it out of R&D and into production just slightly ahead of the competition.

The board features the 371 North Bridge from VIA which enables the 133MHz memory bus frequency support of the motherboard. The memory bus itself can run at either the FSB frequency, which by default is 100MHz, or at 33MHz + FSB which would put the memory bus at 133MHz while the FSB runs at 100MHz. As we've discovered from our review of the KX133 chipset, the 133MHz memory bus does increase performance anywhere from 0% to 20% in normal applications depending on their dependency on a high speed memory bus. The ability to set the memory bus frequency allows PC100 memory owners to use their memory without having to upgrade to PC133 while allowing PC133 owners the added performance benefits of the increased memory bandwidth.

Like all currently available Athlon motherboards, the 7KXA features three 168-pin DIMM slots. The slots themselves are capable of accepting PC100 or PC133 SDRAM as well as VC100 or VC133 Virtual Channel SDRAM. With the latter two being nothing more than vaporware in the market right now, PC100/PC133 memory is really what you can expect to use with the board.

The 371 North Bridge also drives the AGP 4X support claimed by the 7KXA. Our internal tests revealed that the 7KXA is actually using the updated stepping of VIA's AGP 4X core, which is also found in their Apollo Pro 133A chipset revision CE. The updated stepping of the AGP core eliminates all problems with running graphics accelerators in AGP 4X mode, an issue which plagued some of the first AGP 4X boards based on VIA's chipsets but because of the updated core is not present on the 7KXA. The board itself features a universal AGP slot which isn't keyed specifically for AGP 2X or AGP 4X cards, which lets the user install virtually any currently available AGP card in the slot, whether it is an AGP 1X/2X or 4X card.

On the south side of the KX133, we have the 686A South Bridge used on the 7KXA. In our KX133 review, we also discussed exactly what makes the 686A such an intelligent move for motherboard manufacturers -- primarily its highly integrated nature. The 686A South Bridge integrates an I/O controller, an ISA bridge, hardware monitoring functions, along with the usual South Bridge functions all in a single chip. As you can guess, this helps to reduce the overall cost of the motherboard since it removes quite a few chips from the PCB and integrates them into a single chip.

From an expansion perspective, EPoX decided to play it safe with the 7KXA since they took advantage of the integrated ISA bridge of the 686A and included a single ISA slot on the board. In the next few months, expect more and more motherboards to ship without any ISA slots, but this time around, EPoX decided to keep the sole slot on-board for any legacy peripherals you may have. The single ISA slot is shared with the last PCI slot, meaning that only one can be occupied at a time. The 5 PCI slots and single ISA slot are combined with an AMR slot and the aforementioned AGP slot to form the 7KXA's 5/1/1/1 expansion slot configuration (PCI/ISA/AMR/AGP). If you recall, this expansion slot configuration has also been used on ASUS' K7M, which is based on the older AMD 750 chipset.

Like the K7M, the 7KXA features a single AMR slot which is driven by the on-board audio codec. While we weren't familiar with the manufacturer of the codec, it was just as capable as the solutions we have tested in the past -- after all, it's still a software based audio/modem solution. Because of the codec's nature, it does eat up quite a bit of CPU time while processing instructions since there is no hardware to offload the instructions/operations onto.