It’s also been reported that, if your motherboard supports it, setting the PCIe Link Speed to the promontory chipset to Gen2 from Gen3 will fix the issue; that may be a better fix that pci=nommconf but anything running through the chipset will be limited to at most 2 gigabytes/sec.
I have also been experimenting with a very slight FSB underclock (98mhz) on TR boards that support it, that may also “correct” the issue but I’m not real sure yet.