ASUS A7N8X Motherboard

I build, repair and upgrade computer systems occasionally when friends or I need something done. My PC rarely has its covers on, but that's another matter.

Recently I had two to build, and research let me to the A7N8X. With the ASUS name and the nForce2 chipset from nVidia, this board seemed perfect for the task. It had all the usual features and a few I'd not seen before. Main things I picked out were USB2 ports, Ethernet ports (yes ports – the deluxe version of this board comes with two!), 333MHz FSB, memory speeds up to 400MHz, 8x AGP slot, and double wide memory. I think it also had 5.1 or 6 channel sound support, but no one was very interested in fancy sound so I didn't pay much attention. The A7N8X also has comprehensive over clocking support.

The double width memory really caught my eye. Each DIMM is able to store or read eight 8-bit bytes at a time. The A7N8X has two blue memory sockets, and a third black one; if the two blue sockets are populated, then both are (or can be) active at the same time – so 16 bytes can be read or written at once. The memory bandwidth has been doubled at a stroke. This idea isn't new; 30 pin SIMMS used to be used in banks of four, and 72 pin SIMMS and RDRAM in pairs. But this is the first time I've seen DDRAM ganging up for more speed

I coupled the AN78X with an AMD Athlon XP 2100 , an ASUS GeForce4 440MX video card with 64 MB DDR, a WD 80 GB hard drive and two 512 MB PC2700 (333 MHz) DDR, assembled the whole lot into a large case with front USB, a little extra depth so the CD drive didn't overlap the edge of the motherboard, and the hard drive bay positioned so the front case fan directly cooled the hard d rive.

I would have preferred to use an XP with a 333 MHz FSB, but at present these are still only available on processors with very fast clock speeds, and price tags to match. However, when the prices tumble and a 3000 MHz (or faster) chip is available at a believable price (the $600 at time of writing seems a bit much), the board will be ready.

And how did the board do? Well. The manual was comprehensive and easy to follow. Only niggle I had was identifying some of the header pins.. There were several close together, and although each one was clearly defined, on a few occasions it was not immediately obvious which set of pins on the board was being described.

There were no problems using it. It just worked. And was it fast! I had minor problems with CD RW drive, but that wasn't the board's fault. Once that was fixed, it flew. Windows XP installed faster than I'd ever seen (I guess having 1 GB ram may have helped), the motherboard drivers had a nice one shot install package (yes, all motherboard drivers installed at the same time). This saved hours (well quite a few minutes) compared with some setup packages. I also installed the ASUS PC Probe program, which monitors the health of all the critical components, including the CPU temperature, case temperature, fan speeds and power supply voltages. I've had fans fail in the past, with no warning until the system started to crash from overheating. Fortunately there seemed to be no permanent damage, but it's nice to know that situation should not arise with this system.

Then I had to play. The board has a good selection of over clocking features, allowing the CPU speed and memory speed to be set (semi) independently. The video card also has a utility to adjust its speed. I cranked up the front side bus of the CPU from the standard 133 MHz to 140 MHz, 145 MHz, 150MHz… The 2100 chip ran perfectly as an XP 2368 , only giving occasional problems at 155MHz, XP 2450 . That problem was an occasional widow frame that didn't clear properly, so it may well have been the video card that was in need of backing off. So I left the FSB at 150MHz, and delivered two computers which were more than a bit faster than expected. Reluctantly! I liked these systems!

The documentation recommends running the FSB and memory at the same speed. With the CPU running at 150 MHz, the 333MHz memory was running at 300MHz. I cranked that up to 120% which is 180MHz, making it DDR 360. It worked fine but I didn't do any benchmarks to see if overall system speed was affected.

Actually this makes me wonder. If the memory and CPU busses are supposed to be at the same speed, why have support for DDR400 MHz memory when only 333MHz chips are supported?

Caution

Over clocking a CPU voids the warranty (if any) and always generates more heat. If you want to try it, make sure you have a heat sink and fans capable of dissipating the additional heat. And don't do it on mission critical systems! That extra (say) ten percent speed improvement won't make that much difference, but system crashes or errors in the calculation of your tax return might!