Layout and features
The specifications page listed the dimensions of the AB48PN as 305x190mm. The 305mm height of the board corresponds perfectly with a standard ATX form factor. However, the width of the board, a scant 190mm, is a full 55mm thinner than a standard motherboard. You should see this pictorially below:
Notice the dimensions of the retention bracket relative to the PCB ?. That should give you some idea of the PCB space saved by Shuttle. A smaller PCB dictates a lower overall motherboard cost. The only question is whether the manufacturer can successfully integrate the required features effectively. A small passive heatsink is a welcome addition to this board.
Flawless 200FSB operation usually dictates a higher quality of power regulation than the present 133FSB. Much like ABIT, Shuttle have gone with a myriad of high-performance capacitors in and around the CPU socket. A 3-phase PWM (pulse width modulation) controller is used to control the flow of voltage. It would have been nice to see an upgraded 4-phase PWM, a la BH7.
Retention brackets are becoming better with age. We see fewer and fewer boards supporting the plastic pins approach. Rather, 4 screws now hold the retention bracket securely in place. It also makes it easier to remove the bracket should you wish to use a larger cooler.
The locations of both the necessary power connectors is excellent, as they're well out of the way of the CPU socket. Not only does this make for tidier cable routing, it seems logical to group these two power connectors together. You'll notice that they're only 2 DIMM slots. This isn't the major drawback it may seem on paper, as you still have the maximum 4 banks of memory allowed on the i845xx series of chipsets. Having a third slot forces the user to use single-sided memory in slots #2 and #3, if populating all the slots is your aim. Shuttle use the ABIT-like port system. Most other manufacturers have the port notch the other way up.
Two USB2.0 ports on the backplane leave a further 4 to be taken up. The ICH4 provides the necessary controllers, and the headers are present, so it's a little mystifying as to why Shuttle didn't bundle at least one USB2.0 cable. It would have been nice to have the usual PCB markings highlighting which case connector hooks up to certain pins. It is outlined in excellent detail in the manual though.
The manufacturers' favourite 10/100 LAN PHY strikes again. The ever-dependable Realtek RTL8100B is handed the networking duties. To the left you can see a S/PDIF header. This maximises the on-board sound's potential by providing a digital audio connection to compliant devices. Much like a lot of features, the S/PDIF cable is an optional extra. The Realtek ALC650 CODEC sits just underneath the retention bracket. That's the first time we've seen in located there. I'll speak more of it on the following page.
We'd have swapped one of the serial ports for another two USB2.0 ports on the backplane. The 10/100 LAN port has basic yellow and green LEDs that help verify activity and serve as very rudimentary troubleshooting tools.
