I have two east coast USA VPS both running PPTP servers. I connect to them from my 10mbps home broadband connection in the UK but fail to achieve good transfer speeds. I also have a Squid proxy running on both VPS and get on average 2 to 3mbps downstream (upstream from VPS obviously), but using VPN, I get between 0.3 to 0.5mbps. I only need around 1mbps but what I'm getting at the moment is too low.
The two VPS are with different providers - first is a 2GB box from ChicagoVPS (appears to be located in Buffalo, NY) and the second is a 128MB box from Hostigation (South Carolina). Both running Ubuntu, the 2GB box has a few processes running but nothing that uses more than 600 - 700MB of memory; the 128MB box just has PPTP, Squid3 and Webmin running and is running at around 60MB.
Any ideas? Is VPN known to be significantly slower? Encryption on or off seems to make no difference - security is of little importance for my application.