How many MT4 can be run on the VPS?

It is very hard to say.

It depends on:
– How many charts are opened.
– How calculation heavy is the EA.
– How complicated the indicators graphics are.
– etc.

During running your applications, you can monitor the RAM and CPU usage because we provide the VPS with a monitoring software. The RAM and CPU values should remain around 60%. If it is constantly close to 80% than the you need to upgrade for a bigger package.