A very useful profiling tool

Spark is a mod that any server owner, pack maker and performance-centric end user should have. It allows you to easily see current resource usage as well as profiling over a period of time to see what mods are using up the most CPU time.

When making modpacks, this mod can be really helpful for understanding where the performance bottleneck is in packs. It is also really useful if you need to report bugs to mod authors, such as memory leaks, as you can dump the memory or get a brief summary.

As a server owner, this mod proved invaluable for discovering which areas of the world and whose bases were causing server lag, as it has a lag overlay which allows you to easily find problem areas. For the end user it is less useful, but it can help when making large bases to understand why things are slowing down and build things in a more efficient way.

Overall, this is just an incredibly useful tool for server owners and pack makers alike and I highly recommend it.