Question VPN speed is only one-third of the speed without VPN ?

[alanattom]

We use Nord VPN on a W10 desktop. We have 1 gig Fibre.

With Nord running, our download speed is around 400. Without Nord running the download speed is about 925. (The corresponding upload speeds are 400-600.)

What might be causing this download speed discrepancy between VPN and no VPN?

Thanks for any advice!

Alan

 

[kanewolf]

We use Nord VPN on a W10 desktop. We have 1 gig Fibre.

With Nord running, our download speed is around 400. Without Nord running the download speed is about 925. (The corresponding upload speeds are 400-600.)

What might be causing this download speed discrepancy between VPN and no VPN?

Thanks for any advice!

Alan

The overhead required to encrypt your data. That takes a LOT of CPU and memory bandwidth. Traffic that could have direct hardware transfers without the VPN, now has to go to the CPU, be encrypted then get transferred to the network stack. That is the price of a VPN.

And your "one-third" in the title is an exaggeration. Your stated numbers are closer to half.

 

[alanattom]

The overhead required to encrypt your data. That takes a LOT of CPU and memory bandwidth. Traffic that could have direct hardware transfers without the VPN, now has to go to the CPU, be encrypted then get transferred to the network stack. That is the price of a VPN.

And your "one-third" in the title is an exaggeration. Your stated numbers are closer to half.

Thank you for replying! Much appreciated!

I did not realize a drop of 1/2 or so in download speed was normal. I thought the usual "hit" was more like 1/3.

Just so I understand - is the hit due to the capacity / performance of my desktop, or does it generally apply to every VPN user?

Thanks for clarifying for me.

 

[bill001g]

This is purely a function of the cpu and its ability to run the encryption software. It is single threaded also so multicore does not help. The cpu on say a phone is not as powerful so you well get slower results....but does it really matter on a phone nobody downloads gigabytes of data to a cell phone.

The place you see massive slowness is when you attempt to use a consumer router as a vpn box. Many you will cap out at 30mbps both because the cpus are small and because they do not have the encryption instructions built into the hardware.

Not sure if nord supports it but you tend to get better performance using wireguard rather than openvpn.

 

[alanattom]

Thank you, Bill! That was VERY helpful and clear.

My desktop is W10, and it's now almost 8 years old. I'd assumed the download speed degradation while using Nord was entirely due to some esoteric Registry or network setting that only affected me (since the majority of Nord users are apparently pleased with their download speed).

Nord support has been very helpful the past few days, but my hardware configure never came up.

I do not see Wireguard listed as a Nord protocol. My Nord Setting is currently NordLynx which I understand to be Nord's fastest.

Thank you again!!

This is purely a function of the cpu and its ability to run the encryption software. It is single threaded also so multicore does not help. The cpu on say a phone is not as powerful so you well get slower results....but does it really matter on a phone nobody downloads gigabytes of data to a cell phone.

The place you see massive slowness is when you attempt to use a consumer router as a vpn box. Many you will cap out at 30mbps both because the cpus are small and because they do not have the encryption instructions built into the hardware.

Not sure if nord supports it but you tend to get better performance using wireguard rather than openvpn.

 

[BFG-9000]

NordLynx is based on Wireguard.

400Mbps is about as fast as recent consumer routers can do VPN, so basically your old desktop is as slow as a modern wifi router, and you need a faster computer if you want to see faster.

 

[alanattom]

NordLynx is based on Wireguard.

400Mbps is about as fast as recent consumer routers can do VPN, so basically your old desktop is as slow as a modern wifi router, and you need a faster computer if you want to see faster.

Thank you for replying! Much appreciated!

To be sure I understand: when I do get a new (faster!) desktop, Nord download speed will be faster with my same current Ethernet 1G router (we have a separate Google Mesh system for wifi)?

(Also, FYI, I have had some speedtests which showed a faster Upload speed (compared to Download speed)... no idea why that is the case)

Thank you again!