This may seem like a newbie-ish question but I couldn't find an answer for this on google.
I have a server with 128mb of ram. I was wondering if installing memcache will help reduce serverload, say I sacrifice 5-10mb of ram to memcache. Is this even worth it? And if it is, how would I limit memcache to 5-10mb of ram?
I think you should replace apache with nginx first. This will allow you to reduce memory usage, probably even below 64MB, and also server load.
Then, you can allocate up to 60MB remaining memory to memcached, and it should help to reduce load even further.