I was experiementing recently and I found out that the performance of my rendering improved when I had 4 texcoords instead of 2 and x, y, z, 1 instead of just x, y, z.
My question is, is this just coincidence or maybe my own hardware that has this quirk, or is it a general rule of thumb, that you should always have multiples of 4 as vertex data?

Thank you in advance.