Moodle in English: Slow response using Chrome when compared to IE

Slow response using Chrome when compared to IE - 2.8.3 (Build: 20150202)

by Stephen Bloomer - Friday, February 6, 2015, 8:19 AM

This year we have added another 1000 student laptops to our school and Moodle performance instantly took a beating, with CPU load hitting and holding 100% for an hour at a time and pages taking over 5 to 8 seconds to load. We upped the CPU's cores available to the front end server from 8 to 12 and then to 24. Now at 24 processes things are moving along much better.

One of the things we have noticed is that if we use IE the pages load in less than 1 second, but if we use Chrome (under the same circumstances) the page takes about 3.5 seconds to load. Yes 3.5 seconds is not long but it is long when you are sitting there waiting to do things. So if IE loads in under s second, I would believe the server is running fine and it is either something to do with Chrome-IIS, Chrome-PHP, or Chrome-Moodle.

Any ideas?

RAM and other areas look fine.

Front - Windows 2008 R2, IIS, PHP 5.6.0

Back - Windows 2008 R2, MySQL 5.6.19

Re: Slow response using Chrome when compared to IE - 2.8.3 (Build: 20150202)

by ben reynolds - Friday, February 6, 2015, 9:23 AM

I'm responding mostly just to follow this thread. Moodle does not recommend IIS. I want to see what others have to say.

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Re: Slow response using Chrome when compared to IE - 2.8.3 (Build: 20150202)

by Tim Hunt - Friday, February 6, 2015, 4:58 PM

It is very odd for Chrome to be slower than IE, and for the difference in browser to affect the server like that.

Can you open Chrome developer tools (F12) and switch to the Network tab. That will show you all data that Crome is fetching from Moodle, with a time-line.

Then do the same for IE, there are similar tools there.

What seems to be different between the two? (Perhaps you could post screen-grabs of the two here?)

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Re: Slow response using Chrome when compared to IE - 2.8.3 (Build: 20150202)

by Stephen Bloomer - Saturday, February 7, 2015, 10:18 AM

Thanks for that. I did not know about that option in Chrome. It has given me a lot of info to go through. Could be a theme issue but I need more time to look

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Re: Slow response using Chrome when compared to IE - 2.8.3 (Build: 20150202)

by ryan sanders - Saturday, February 7, 2015, 6:12 AM

is there an issue with javascript? or ad blocker? (what happens with javascript off) in both browsers? due you have some sort of ads or tracker software? that is auto loading via some script? at times flash, java applets, have been known to crash some websites suddenly. some "hacker attempt" or just plain badly written code.

due to cross browser compatibility and various javascript scripts to handle it... some due have errors from time to time... it might be moodle. but it could be another javascript you included... for example ads. but it could be for web tracking software or like.

<quote>(under the same circumstances)</quote>

i know being nit picky but i gotta ask, to ask...

firefox? chrome? ie? all installed on same device, and each browser checked for times? other words already installed, standing in classroom, with same single from a given wifi connection. and each browser checked for time. ((i ask, only for network issues? computer connecting to network from different routers / switches for the tests))

again gotta ask... have you cleared all history, all cache information on both test machine operating system and browsers, and on server/s including moodle itself? have your done a local physical restart of test machine and servers?

have you went into firefox and/or chrome and in address bar i want to say typed in "config" and pressed enter. and reset all options to default? are there any extensions installed? activated and/or deactive? sometimes i gotta love antivirus software, firewall software, even adobe software have had issues with.

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Re: Slow response using Chrome when compared to IE - 2.8.3 (Build: 20150202)

by Stephen Bloomer - Saturday, February 7, 2015, 10:14 AM

I am not at work today, so I will do more testing during the week. Our network is fast. 10GB to all buildings, 1Gb to all ports and we have tested during load and when there is no load and it does not seem to make a difference. Testing from home and after hours and we always get the same response where Chrome is about 3 times longer to load than IE. Our site is as close to stock standard as I can keep it. No add systems installed etc. And again we are trying from many computers and different OS and setups ect. The only thing not standard is the theme Essentials which is used.

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Hardware and performance

Slow response using Chrome when compared to IE - 2.8.3 (Build: 20150202)