One of the most important things for your tiny VPS is the initial RAM usage. I mean, how much RAM is used by your system. This is why I decided to test it on a low-end VPS.
I used VPS from Ramnode with 128MB of RAM. I used VPS boxes from DigitalOcean as well as from Vultr. Unfortunately Ramnode is the only one from these three providers who offers minimal distributions for CentOS 6 and 7, Debian 7 and Ubuntu 14.04. I tested both 32-bit and 64-bit versions. Unfortunately CentOS 7 is available only in 64-bit so I couldn’t test its 32-bit version.
This is how I tested:
First, I installed desired minimal distribution. In the second step I restarted the system and checked the RAM usage. You can see everything in graph bellow.
As you can see CentOS 6 x64 uses almost two times more RAM than Debian 7 x84. If you want to save some RAM, you must use the 32-bit version of your favorite system.