Hi,
To align the CPU frequencies to performance mode you can run this one liner, that way you can drop the -F flag :
for CPUFREQ in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do [ -f $CPUFREQ ] || continue; echo -n performance > $CPUFREQ; done
I'm pretty sure it will give you better results, 3600 MB/s equals 28.80 Gbps which is decent, depending on the card you're using. You might also want to raise the port MTU to 4k to have better results.