PPTP and OpenVPN are very popular these days because they are easy to set up and use. OpenVPN is also a free and open-source software application.
PPTP can be set up on most operating systems and devices (like android based mobile devices) while OpenVPN may not be available for some devices.
The main difference users can notice is that OpenVPN has an advantage over PPTP because is more flexible. The OpenVPN protocol uses special configuration files for each server you want to use, even allowing users to choose between the UDP and TCP ports. As more and more countries are trying to block internet access (through the VPN) within that specified country, by blocking either the protocols or ports. Unlike the other two (PTPP), OpenVPN can be configured in such a way that the user can overcome almost any problem.
OpenVPN uses SSL/TLS security for encryption and provides many security and control features. It provides encryption of both the data and control channels using the OpenSSL library. It can also use the HMAC authentication feature to further enhance security.
PPTP or Point-to-Point Tunneling Protocol is a method used for creating Virtual Private Networks over the internet. It is developed by Microsoft. With its use, users can remotely access corporate networks from any Internet Service Provider (ISP) that supports the protocol. PPTP works at the data link layer of the OSI model. The positive of this protocol is that it can be configured in your PC/Mac/Device.
When used in its default UDP mode, OpenVPN provides the best performance.
The speeds are almost the same.