Speed
Posted: Sun Mar 13, 2011 3:45 am
"Why can't I have more speed?"
Users are asking, and I don't have a good answer. I have spent hours researching this issue, coming up with almost nothing. One guy on speedguide.net went crazy trying to get more speed, came up with very little. I couldn't believe how many different ideas he tried to make OpenVPN faster. http://forums.speedguide.net/showthread ... ng-openVPN
I have a Quad-core server. 4GB of RAM. Centos. 1Gbps port. Multi-terabyte bandwidth allowance per month.
I run four OpenVPN instances on the server. No instance has ever shown me more than 10% CPU. RAM does get used, but we keep 275Mb free. I run Blowfish encryption.
I personally get 11Mbps down from my ISP. On the VPN, it's more like 2.5Mbps down. Not that I'm complaining, but where did the extra bandwidth go? Port 80, 1194, 443, 53, TCP, UDP, I've tried every combination. My OpenVPN server is capable of 400Mbps+. My home PC CPU for the OpenVPN process is minimal (1%).
So why is VPN slower than native connection?
I mean, I understand that an encrypted connection running on a machine that hosts 100 VPN sessions is going to be slower than the native ISP bandwidth. Still, if the server is not the limit, and the client PC is not the limit, then what is?
Users are asking, and I don't have a good answer. I have spent hours researching this issue, coming up with almost nothing. One guy on speedguide.net went crazy trying to get more speed, came up with very little. I couldn't believe how many different ideas he tried to make OpenVPN faster. http://forums.speedguide.net/showthread ... ng-openVPN
I have a Quad-core server. 4GB of RAM. Centos. 1Gbps port. Multi-terabyte bandwidth allowance per month.
I run four OpenVPN instances on the server. No instance has ever shown me more than 10% CPU. RAM does get used, but we keep 275Mb free. I run Blowfish encryption.
I personally get 11Mbps down from my ISP. On the VPN, it's more like 2.5Mbps down. Not that I'm complaining, but where did the extra bandwidth go? Port 80, 1194, 443, 53, TCP, UDP, I've tried every combination. My OpenVPN server is capable of 400Mbps+. My home PC CPU for the OpenVPN process is minimal (1%).
So why is VPN slower than native connection?
I mean, I understand that an encrypted connection running on a machine that hosts 100 VPN sessions is going to be slower than the native ISP bandwidth. Still, if the server is not the limit, and the client PC is not the limit, then what is?