After using OpenDNS name servers for months at work I started to notice that page load times at home (on a much slower connection) were considerably more “snappy” with my ISP provided DNS servers. A quick Google brought up the comprehensive Open Source namebench DNS benchmark tool.
A run of namebench resulted in a pretty html file with numbers and graphs that confirmed my suspicions. My ISP’s (Comcast) DNS servers were 174.4% faster than OpenDNS on average, with Google’s Public DNS coming in a close second place.
It should be noted that namebench is rather smart and it rifles through your browser history in order to compile a personalized set of domains for its testing, so my results are potentially unique – and this is just one test (actually I did three, I also used Alexa top domains for a source to avoid DNS caching – and the results were all similar), at one location. Although once I switched to my ISP’s DNS servers I experienced a noticeable difference in page load times. Not to mention that my results may change in the future due to server load, poor caching, etc. But with OpenDNS, there was always a slight wait before a page would even start to load, and now that wait is gone. And that’s on a 36Mbps downstream connection.
My points are simple:
- Switching to OpenDNS (or any other DNS service) may be a bad thing.
- Your DNS server does matter.
- namebench is awesome.
It may be a matter of milliseconds but it all adds up, many large websites require dozens of DNS queries for ads, images, scripts and more. Do your own testing before believing the hype.
Regardless, OpenDNS is still a great service: if I ever have the need for a basic content filtering system I will turn to OpenDNS.
Download namebench (for Windows, Mac, or Linux/Unix) and see for yourself how your current DNS stacks up.