The key which differentiates the Gigabyte GA-8KNXP
Ultra-64 from all other consumer i875P motherboards is the Intel 6300ESB
(Hance Rapids) southbridge. The Intel 6300ESB has support for the usual connectivity we expect
like Serial ATA, Ultra/100 IDE, AC'97 audio and a half-dozen USB 2.0 ports.
makes a motherboard with the Hance Rapids Southbridge special is obviously its
support PCI-X slots. The standard 32 bit PCI interface remains more
than sufficient for the applications most users demand of their home or office
PCs, but some devices just demand more bandwidth than a 32-bit PCI
slot can offer up. This is where PCI-X comes in. It actually stands
for PCI eXtended, and extended is a good way to think about PCI-X cards,
because that is exactly what they are, an extension of the PCI bus.
PCI-X should not be confused with PCI Express, the two are completely different,
and not interchangeable although the names sound very familiar when spoken aloud.
PCI-X slots are intended for workstation situations, and allow the
PC to advantage of higher bandwidth 64bit PCI-X devices. These could
be Gigabit network cards, fibre channel, SCSI or RAID cards, or other more specialized devices that would be more at home in a server environment than under a
desk. Running on 3.3V (as
oppose to 5V for regular PCI rev 1-2), PCI-X is the 64 bit solution that runs at
66 MHz. Each PCI-X slot provides 266MB/s of bandwidth, double that of PCI, and has
a 533MB/s connection to the southbridge, so there is plenty of bandwidth
to go around.
As you probably guessed,
the PCI and PCI-X slots on the GA-8KNXP Ultra64 do not share the
same bus to the Intel 6300ESB. Rather, the two PCI-X slots have their own private
and direct connection. In fact, the onboard Adaptec AIC-7902 Ultra/320 SCSI controller
makes use of its own PCI-X connection to the Intel 6300ESB, rather than sharing the PCI
bus with other system devices. With a maximum throughput of 320MB/s, the Adaptec
SCSI controller could potentially saturate a PCI bus.
There is much more to this
topic than we have covered here, and configuring a computer system with SCSI
drives can certainly bring about certain performance enhancements. That is
beyond the scope of this review however. Now, let's have a look inside the
GA-8KNXP Ultra's BIOS.