Hi Liasgm, are these physical servers or virtual servers?  I will assume physical as you say there is a physical switch between them.  There is always a perfomance hit if the database and runtime are split (usually around 30%).  If you can put them both on one server that would be ideal.  If not, then you would ideally need a 10 to 40gbps network connection between them (the lower the latency and higher the throughput the better).

https://online-help.sagex3.com/erp/12/howtoguides/en-US/technical/Architecture%20and%20system%20requirements/Content/How-to%20guides/Platform/Architecture%20guide/Topic%205%20Technology.htm

"Server-side network requirements
A 10 Gbit/s link is highly recommended between the different process servers and the database server hosting the Sage X3 folders data.

For other components, a Gigabit link is recommended but it can work with lower bandwidth and higher latency."

Thank you, i will upgrade the switch to a 10Gbps switch. the traffic is now normal since several days, we were hitting the 1Gbps for a 3 days in a row, users were unable to do anything and were complaining all the day and we tried to figure out the cause of this issue but couldn't figure it out, then suddenly it went down to about 50Mbps in average! and it is very stable now.

i don't know if this behaviour is normal and if we are going to hit the 1Gbps again, i will upgrade the switch as suggested in the link that you have shared.

Thank you Carl Herrmann 

Thank you, i will upgrade the switch to a 10Gbps switch. the traffic is now normal since several days, we were hitting the 1Gbps for a 3 days in a row, users were unable to do anything and were complaining all the day and we tried to figure out the cause of this issue but couldn't figure it out, then suddenly it went down to about 50Mbps in average! and it is very stable now.

i don't know if this behaviour is normal and if we are going to hit the 1Gbps again, i will upgrade the switch as suggested in the link that you have shared.

Thank you Carl Herrmann 

What patch level of Sage X3 is your solution? Runtime, Syracuse, Print Server, AdxADMIN?