On some Intel x58 chipsets, the DMA performance on the Base TRD fluctuates and is lower than expected. This is believed to be due to intel-iommu having issues freeing up DMA page tables.
This issue can be resolved as follows:
When Fedora 16 Live is booting
i. Press tab for full configuration options on menu items.
ii. Add iommu=pt64 at the end of the line vmlinuz0 initrd=initrd0 ...rd.md=0 rd.dm=0
iii. Hit the enter key to boot with this option.