[Anders Rydmell]

Hi!

I think you have mixed Gb/s (gigabits/sec) with GB/s (gigabytes/sec) for the PCI Express bandwidth.
One PCI Express Gen2 x16 lane slot has 8 GB/s of bandwidth. That is equal to 64 Gb/s.

See https://en.wikipedia.org/wiki/Data_rate_units and https://en.wikipedia.org/wiki/Pci_express#PCI_Express_2.0 and https://www.intel.com/Assets/PDF/datasheet/321328.pdf section 1.1.4

The Mac Pro 2010 is using the Intel 5520 chipset with a total of 36 PCI Express Gen2 lanes.