The DFI PA61
VIA Apollo Pro133 mainboard
Wednesday, December 15, 1999
There are manufacturers that choose to be prolific, and innovative, and there are others that choose to be more conservative. DFI, a company that I really like, offers one of the most diverse set of boards on the market. DFI truly does not lack for choice, with their offerings both for the simple and ordinary, and for specialty boards that support multi-processor systems, and that have SCSI controllers imbedded on-board. As well, DFI maintains a division dedicated to developing machines for the most demanding of industrial tasks. All that said, the motherboard we'll be analysing is dedicated towards the more conventional PC-platform. The DFI PA61, then, is a slot 1 board, based upon the VIA Apollo Pro133 chipset. Without further ado, let's put our subject under the spot.
The PA61 expansion possibilities are supported via its 4/3/1 slot design. Thus 4 PCI slots, 3 ISA slots, and 1 AGP port. As with most slot 1 motherboards, the PA61 sports 3 168-pin DIMM sockets for memory expansion purposes. Just between you and me, in this era of the decline of ISA devices, I really have to ask why the team at DFI chose to integrate 3 of them into their board. In my opinion, DFI must have somehow ended up with a huge surplus of ISA connectors in their warehouse. Whatever the reason, they did finally decide to install no fewer than 3 of the things on each board. If nothing else, one must give them credit for a distinct advantage over their competitors in the ISA department. It certainly seems, though, that DFI chose to employ several ISA slots, at the expense of PCI expansion. At this point, many manufacturers are in fact cutting ISA out of their production boards all together, or else installing a single such slot.
Configuration of the PA61's clock frequency is done from the BIOS sub-menu labeled "Chipset Features Setup". The PA61's clock multiplier is set via a series of DIP switches labeled SW1. As always, take into account that Intel has now engineered its processors to ignore the clock multiplier setting; thus there is no need to spend time setting a feature that will be ignored. One thing to note, normally with this sort of board, there is an option within the BIOS to set the operating frequency of the memory bus to a value equal to that of the system bus, plus or minus 33Mhz. This option doesn't work with the PA61. It's thus impossible to vary the frequency of the memory bus. I even flashed the BIOS, wondering if this omission was possibly an accidental bug in the BIOS, but to no avail. The memory bus of the PA61, then, functions solely, and uniquely at par with the frequency of the front side bus. Another thing to note, this type of board also usually offers a set of jumpers, through which that allow the setting of the front side bus to be determined automatically, or forced to 100Mhz, or 133Mhz. With the PA61, a single jumper (JP2) is dedicated to this job. The jumper offers two settings: automatic adjustment by the system, and a position describer as for factory testing only, and that is thoroughly undocumented. When I did dare to change the jumper setting of JP2, I was not greeted by a start-up screen indicating the memory frequency, as normally seen on most of the PC133 ready motherboards, and so there is no way of knowing what exactly what was transpiring on board.
Available clock frequencies, include: 66 - 75 - 83 - 100 - 103 - 105 - 110 - 112 - 115 - 120 - 124 - 133 - 140 and 150MHz. Clock multiplier are available from 3.5X to 8X in steps of .5X.
Finally, no option is provided for adjusting the processor's core voltage..
Next: Additional Features.