asymmetric DMA speed on myrinet

Hello. I've seen that the DMA speed of Myrinet NIC is different based on 
the direction of DMA. 
L2E(from NIC to host memory) is faster than E2L(from host memory to NIC), 
especially for large messages.
Is it a Myrinet specific feature or a wide-accepted one?
(I guess giving higher speed to L2E might be good since it can reduce 
the number of packets in the network and resolve the congestion of the network.)
Can I balance the DMA speed with simple operation to special registers
on Myrinet NIC or any other method?
Thanks.

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with regards
sang