I hope I have placed this technical question in the correct section. I simply do not know where else to put it.

This is a question about generating vanity addresses (not mining): generating keys until you get the result you want.

I rent a Ubuntu VPS with 6 cores. This is not a dedicated server. Currently I get a speed of about 2.8Mkeys/s.

My understanding is, that in a shared VPS model, the overall CPU and memory are shared across all users. So I have my own IP but the capability of the resources I use depends on what other users are doing (with other IP addresses). That's why my speed can vary (it has been as high as 4.5Mkeys/s and as low as 2.1Mkeys/s).

What do you think would be the most cost effective way to generate a higher number of Mkeys/s?

A dedicated server with a certain number of CPU cores (how many cores?)

And what's the difference between KVM or OpenVZ VPS's? My impression is that KVM is superior but why?

Thank you.