12-21-2017, 10:08 AM
Hi,
I have been experimenting with enabling Bifurcation on my MSI X99A motherboard. This motherboard has an IOU2 controller that routes to either the onboard M.2 Slot or the PCIE#5 slot of which 8X lanes are shared. Unfortunately its either one or the other. You can not split the 8X into 4X such that both are sharing the same PCI-E highway. You can either set the M.2 to PCH control or not have PCIE#5 operate. I believe they did this such that with a 28 lane cpu there just isn't enough lanes to split but there is enough with a 40 lane cpu.
So my next step was to figure out how bifurcation works and with the help of AMIBCP was able to see that there was 4 IIO controllers each with their own IOU2 set which could be set to bifurcate the lane in half to 4x4x on the same PCI-E Slot but not split between M.2 and PCI-E#5. Just as the PCIE#3+#4 can operate between 16/0 and 8/8 operation there must be setting somewhere that can hack the PCI-E#5 + M.2 to operate at 4X/4X unless of course this is hard wired then there is no hope.
Thanks
I have been experimenting with enabling Bifurcation on my MSI X99A motherboard. This motherboard has an IOU2 controller that routes to either the onboard M.2 Slot or the PCIE#5 slot of which 8X lanes are shared. Unfortunately its either one or the other. You can not split the 8X into 4X such that both are sharing the same PCI-E highway. You can either set the M.2 to PCH control or not have PCIE#5 operate. I believe they did this such that with a 28 lane cpu there just isn't enough lanes to split but there is enough with a 40 lane cpu.
So my next step was to figure out how bifurcation works and with the help of AMIBCP was able to see that there was 4 IIO controllers each with their own IOU2 set which could be set to bifurcate the lane in half to 4x4x on the same PCI-E Slot but not split between M.2 and PCI-E#5. Just as the PCIE#3+#4 can operate between 16/0 and 8/8 operation there must be setting somewhere that can hack the PCI-E#5 + M.2 to operate at 4X/4X unless of course this is hard wired then there is no hope.
Thanks