Asus NCT-D (E7525), Continued
Broadcom names its latest PCIe GbE chip the BCM5751.
Since Asus decided against deploying the 6700PXH, there is an additional x4 PCIe slot left for future upgrades.
Asus decided to use the cheaper 6300ESB Southbridge.
The 6300ESB offers two 64 Bit PCI slots for the NCT-D. The Southbridge is operated via Intel's Hub 1.5 protocol at 266 MB/s which could cause a bottleneck after checking the number of additional components: There is an USB 2.0 controller from VIA, a Firewire chip and a SATA II controller with four ports (300 MB/s each). Using all these components simultaneously would exceed the 6300ESB's interface bandwidth.
The Texas Instrument chip is a 1394a part.