Is it normal that the PCIE functions from the DE5-net user CD are extremely slow?

I have been testing the C functions PCIE_Write32( ) and PCIE_DmaWrite(). The PCIE_DmaWrite() function seems to reach a maximum rate of 515 Kbytes/s even with adress allignment and sufficient transfer size. The PCIE_Write32() functions are surprisingly faster with 2.3 Mbytes/s, wich is still extremely slow for PCIE. Is this normal?