Forge 1.12.2 server RAM allocation

[Malopig]

I have setup a 1.12.2 forge server 

occasionally it throws a '[Server thread/WARN] [minecraft/MinecraftServer]: Can't keep up! Did the system time change, or is the server overloaded? Running 2316ms behind, skipping 46 tick(s)' and a ram usage spike 

I have 32gb of ram installed in my pc and on a vanilla server l would normally just make a run.bat file but it is not working

 

When I launch the run.bat

C:\Users\Max\Desktop\1.12.2 server>java -Xmx4G -Xms4G -jar minecraft_server.1.12.2.jar nogui

C:\Users\Max\Desktop\1.12.2 server>PAUSE
Press any key to continue . . .

 

The run.bat file contains

java -Xmx4G -Xms4G -jar minecraft_server.1.12.2.jar nogui
PAUSE

Any advice would be appreciated

[Ugdhar]

I am unsure what you are trying to say after "When I launch the run.bat", is it failing to run and just immediately saying press any key to continue? Or is it because it is launching a vanilla server, not a forge server? Which is what will happen (if it is launching something), since you're specifying the vanilla jar file, and not the forge one.

Please read the FAQ and post logs as described there, it helps to see what's going wrong.