[dpdk-users] HOW performance to run DPDK at ARM64 arch?

[金塔尖之鑫]

recently, I have debug DPDK18.08 at my arm64 arch machine, with 
DPDK-pktgen3.5.2.
but the performace is very low for bidirectional traffic with x86 machine

here is my data:
hardware Conditions：
        arm64:    CPU - 64 cores, CPUfreq: 1.5GHz
                       MEM - 64 GiB
                       NIC - 82599ES dual port
        x86:        CPU - 4 cores, CPUfreq: 3.2GHz
                       MEM - 4GiB
                       NIC - 82599ES dual port
software Conditions:
         system kernel:
                  arm64: linux-4.4.58
                  x86: ubuntu16.04-4.4.0-generic
         tools:
                  DPDK18.08, DPDK-pktgen3.5.2

test:
       |----------|                bi-directional                |-----------|
       | arm64 | port0 |           < - >            | port0 |     x86   |
       |----------|                                                     
|----------|

result
                                  arm64                                   x86
Pkts/s (Rx/Tx)            10.2/6.0Mpps                       6.0/14.80Mpps
MBits/s(Rx/Tx)             7000/3300 MBits/s             3300/9989 MBits/s

Questions：
1、Why DPDK data performance would be so much worse than the x86 architecture in 
arm64 addition?
2、above, Tx direction is not run full, Why Rx and TX affect each other？