Review of Slot 1 Motherboards with Intel 440BX Chipset - Spring 1998

Supermicro P6DBS

Supermicro's P6DBS dual BX motherboard is another impressive piece of hardware, big and well equipped. It comes with onboard dual UW SCSI and a RAIDPort II, making it a nice worksation or server motherboard. It's of course equipped with 4 DIMM sockets as well.

Unfortunately there was a little problem with Toshiba SDRAM chips, the board only ran it at slow settings and even that wasn't too stable. It seems to be a common problem, because the Iwill and one of the Tyan dual CPU boards ran into the same trouble. It worked without any problems when using the Samsung PC66 SDRAM, which shows that the RAM timing is not a really serious issue. However, you could be facing problems when not buying the right PC100 SDRAMs.

The compatibility testing turned out to be some kind of nightmare, but I can't really blame Supermicro in the first place, since the problems were mainly caused by AMI's wonderful WinBIOS. The WinBIOS has got a serious problem with the IRQ assigning for the different PCI slots, making my default configuration completely impossible to run. Instead of this I had to play PCI card jokey. There is an option of disabling the USB IRQ in the BIOS setup menu, but USB still grabs IRQ 9 regardless what setting you choose. The same is valid for the onboard SCSI, which has a 'disable' setting, but after that IRQ 10 is still used by it. Additionally, AMI WInBIOS would not let the ISA PnP network card connect to a network unless it's using IRQ 5.

Although this board showed the best perfomance amongst the dual boards, the problem with the SDRAM as well as the huge compatibility problem were strong enough destroying any chance for the P6DBS of entering any recommendations list.