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Help understanding divergent test results - susskind - 08-14-2012 05:51 AM

Idaho, DSL:

In IE, it says CDN detected but that the images aren’t compressed:
http://www.webpagetest.org/result/120813_3R_GA9/

In Firefox, it says no CDN detected, but that the images ARE compressed:
http://www.webpagetest.org/result/120813_JY_GC9/

In chrome, it says CDN detected and the images are compressed:
http://www.webpagetest.org/result/120813_8R_GZA/


Can anyone explain this? I also don't understand why the times are slower in Chrome and Firefox when in my experience chrome is a much faster loading time than IE.

Thanks in advance!


RE: Help understanding divergent test results - pmeenan - 08-15-2012 12:16 PM

Looks like the CDN flip-flopping depends on the ads being served at any given time. Roughly half the static content is being served from a CDN so it doesn't take much to push it to either side of the detected/not line - http://www.webpagetest.org/result/120813_JY_GC9/1/performance_optimization/

You shouldn't use just one run to compare browser performance - try 9 and see if IE is still faster. I'd also recommend capturing video and then doing a comparison that way to see which "feels" faster because it's possible that the technical measurements are slower but the visual experience may not match.


RE: Help understanding divergent test results - susskind - 08-16-2012 12:34 AM

Thanks for the response!

We don't have any ads served on our website so I'm not sure if that's it. Also why does it say images 100/100 are compressed in firefox but 38/100 in IE.

I'm going to try the video comparison.

Do you have any other recommendations on improving our speed? We went on CloudFlare but really haven't seen much of any change in page load time.


RE: Help understanding divergent test results - pmeenan - 08-17-2012 11:48 PM

The content served to IE and Firefox are quite radically different. It is possible that Cloudflare skipped a lot of the optimizations for IE8. It's also possible that they were served over a SPDY connection in the firefox case which is something that WebPagetest doesn't have visibility into yet (That really long blue bar in the firefox test is probably a SPDY connection).


RE: Help understanding divergent test results - damoncloudflare - 08-21-2012 10:11 AM

"Do you have any other recommendations on improving our speed? We went on CloudFlare but really haven't seen much of any change in page load time."

Did you only recently add the site to CloudFlare? Please keep in mind that caching might actually take several days or so to build out.