We have been working on a solution to address this problem for the last couple days. I am hoping to get the code change out by end of this week. During the last couple weeks, we have noticed many memory leak issues from tensorboard, it not only leaks memory with large directories, but also with directory that has a single large tf event file. So pointing it to logs folder won't fix all the leaks.
After the our tensorboard bandage is out, I will see if I can help fix those actual memory bugs in tensorboard and contribute the patches back to upstream.