Intel PWLA8492MT PCI-X 2-Port bottle neck ?

[iron31]

Hello everyone.

To maximize bandwidth and use my free PCI bus in my motherboard, I installed an Intel Dual Ethernet PCI card:

But performance is lower than my ethernet card intel single PCIe x1 and in board RT 8111d!

Read speed ZFS raidz1 to w7 ssd via Samba :

Intel EXPI9301CTBLK single Ethernet : 100MB/s
RT In board : 84 MB/s
Intel PWLA8492MT PCI-X 2-Port : 60MB/s

I have two questions:

Is this is the PCI bus of my motherboard that limits the performance of my dual ethernet PCI card?

Intel Dual PCIe cards Ehernet all need a PCIe x4 and my motherboard is devoid port. The 2 PCIe x8 have M1015 SATA Controler.
Is it possible to put Dual Ethernet card PCIe x4 in a PCIe x1 slot (by cutting a part of the card bus) and enjoy all the bandwidth?

Thank you all!

[b0ssman]

well

the pci bus on your board is 32bit 33mhz. thats a theoretical maximum of 133 mbyte/sec. This is shared accross all the pci slots. hence the lower transfer speed that you are seeing
the card is a 64 bit 133mhz but you will need a special motherboard to take advantage of that.

it would be better to get 2 pcie intel network cards.

[iron31]

Thanks
I command 2 intel NIC PCIe x1