Topic: PCI or PCIe on x79 chipset

Currently I’m running a Multiface I + PCI. Does somebody know if there is a gain in ASIO performance at low buffer size operation (32, 64) when replacing the PCI for a PCIe?
I use an Intel® X79 board so I guess the PCI is bridged.

Or would it be even better to go for an AIO to get higher performance at small buffer sizes?

Thank you.

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RME AIO
P9X79, i7 3930K, 16GB, HD6450
Windows 7 pro 64 Bit