I run a vanilla Minecraft server and it crashes a lot. I was wondering if having a low amount of RAM could be the cause of my server crashes. I run it on a desktop computer but my computer only has 4gb of RAM! Bonus info just for you: Windows 7, 64bit OS.
RAM is not everything with a Minecraft server. It also depends on your CPU, internet speed, and what else is running on your computer. If you are running a lot in the background, and have an older CPU, that may be causing the crashing. For RAM, if you are not dedicating the server enough RAM, then it will crash pretty fast.
I have a 3GB RAM VPS Server from CreeperHost.net - I have 2.4 GB of that RAM allocated to Minecraft. With this I can get 40 players on with no lag.