# Limitations

The following are a few limitations that you can encounter while using In-Memory DB:

* You cannot use multiple In-Memory DB instances simultaneously, but each for a particular use case.
* You have access to ten default In-Memory DB instances, which are numbered to differentiate them. However, it is not possible to add or rename the instances after creation.
* The total upper limit for CPU cores depends on your quota. A single instance cannot exceed 16 cores.
* The total upper limit for RAM depends on your quota. A single instance cannot exceed 32 GB.
* The upper limit for storage size is 2 TB.
* Storing In-Memory DB instance backups in an IONOS Cloud Object Storage is limited to the last seven days.
* The following IP ranges cannot be used with In-Memory DB services:
  * `10.208.0.0/12`
  * `10.233.0.0/18`
  * `192.168.230.0/24`
  * `10.233.64.0/18`