We run on a Xeon 1270, with 16GB of ram and hardly ever use more then 30% of it. Yet for quite a long time we have had major TPS issues, Down to 2/7TPS average. We never use more then half of our ram, and we have another server on the same machine that dont experience this. We almost always have 60+ online. Here are some pictures (I marked out plugins its not for sure) Showing Really bad TPS:
