How much Is important the distance between sending request position and server position?

Question

I have a website, usually the users of my website are from Iran. Now I want to know, buying a VPS from a near country is important?

For example: Is it better to I buy a VPS from Digitalocean or OVH website? DigitalOcean's servers are in Holland (ping of Holland from Iran is 200ms) and OVH's servers are in Canada (ping of Canada from Iran is 400ms).

Now I want to know, the distance between users and server (geographically) how much is important?

Answer 1

Distance doesn't always affect latency; however, it seems you have already tested and found a correlation with your two potential vendors. To better serve your customer-base, lower latency is better (regardless of physical distance), so I would go with DigitalOcean.

With that said, if there is some other reason you'd prefer to use OVH and your users will mostly be connecting from mobile devices over congested 3G cellular networks (or other slow links), then you could probably get away with the 400ms latency.

Assuming you're using HTTP(S), remember each bit of the site that is downloaded is a new connection, so each image file, CSS file, Javascript file, video file, etc. is going to take that long between each part of building the connection and downloading the file, so these latency times will be repeated several fold to download an entire website.