How Fast Are Vertex Buffers?

[singularis]

I have been coding with DirectX8 for a while and have always used user primatives, this is because it requires less code. I then came across a website that stated that using vertex buffers could speed up your program due to something with the graphics card (I will look it up).

My main question would be, is it worth having a tiny vertex buffer with only 4 coordinates?

[jcis]

My main question would be, is it worth having a tiny vertex buffer with only 4 coordinates?

No, Vertex Buffer uses Hardware memory in the Graphics card, and old ones doesn't support it. Also, 4 coordinates? you don't need it, the main advantage about Vertex Buffers is speed, the hard work is sent to the Graphics card when using a big meshes with many many vertexes.
I don't know about DX but OpenGL has other ways to gain speed, like creating Linked Lists. Note that Linked Lists and Vertex buffers should never be used together.