Separate table by often changed / not often changed data? I have a application which querys different gameservers, and stores for example if the server is online, and how many players are connected. But of course there is also data which is changed rarely.

Currently I have all this in one table.

So my question is: does it make a performance difference if I split this table up, so that often changed data is in one table, and things like the description in another?

(I have to add that I always only select the data I need, so not like Select *). But when I select the data I often have to select the often changed data + the rarely changed data at once.
Yes, it will make a difference.  How big a difference will depend both on how many rows the table has and how many columns as well as how frequently the table is read from and updated.  Depending on the database, the block size and how many rows are updated at the same time could also be factors.  

Keep in mind the overhead you are introducing by splitting the table for how often the data will be queried separately vs how often it will need to be joined and the performance requirements of various reading and writing activities.