Performance issues with v18 compared to v17.5.

Hi,

 

Snort seems to be using way more CPU than before, on v17.5 I'm able to get 30MB/s throughput with generalpolicy on IDS/IPS, while using way less CPU than v18.

 

Hardware: Intel J1900, 4GB RAM, Intel 82576 NIC.

Sophos XG Home License.

 

First picture is with 30MB/s throughput (which is the limit of my Download throughput), second picture has take a while after, using 26MB/s, v17.5:

 

On v18 the maximum i can get is 18MB/s with the same policy while Snort almost using 100% of the CPU:

 

I've used Iperf3 to test LAN => WAN throughput. (Iperf3 Server on a 1/1 Gbit/s VPS)

 

I noticed that since v18 have the new Xsteam engine, the Snort RAM usage is lower than v17.5. Will increasing to 8GB of ram, (6GB usable), make any difference on it ?

 

Thanks,