(DMI) was the link between the NB and SB on the old boards, so it did not need to be very fast. QPI on the X58 does everything, so it must be much faster (on 1156, PCI-E lanes go directly from CPU to video cards).

The "lack" of speed compared to the QPI is just okay since the DMI connect's the "low speed devices" from the p55 chip to the CPU... ^-^