View Full Version : Rendering in thin client browser slow

25 Jul 2013, 10:54 AM
Anyone know what provides the horsepower to render Fusioncharts, grid and panels on a thin client? This brick is a 1ghz HP model with Linux core and Firefox browser. My app has 3 charts, a grid and 4 panels. The panels have 4 display only fields. Every 30 seconds new Ajax calls made to server to get new data to use.

When this runs on a real Windows desktop (3ghz), either Chrome or IE, the rendering of the new data is very fast, you don't even see the load masks as the charts, grid and panels are rebuilt. But on this brick it is a 100 times slower (maybe 5 seconds). Doesn't matter if using Flash or letting it chart with javascript, both same speed.

Does the browser use the main CPU or rely on a graphics card to get this done? Is it a temp memory or cache issue? I'm trying to figure out what resources a full desktop has that thin client is missing in this arena.

Anyone with any experience with something like this, I'd sure appreciate some feedback. We are trying to implement a 24/7 "TV like" metric dashboard for our shopfloor. No user interaction is required, which is why we are trying to minimize cost with brick and imbedded browser.

We just ordered a brick with imbedded Win 7 and with a decent graphics card for our next test. That will also get Firefox out of mix. Besides being slow, it eventually crashes the entire brick with "out of memory" error. We found posts on Mozilla forum talking about crashes like this dating back to 2007 and people were still complaining in 2011. Have no idea if fixed yet, I'd say not based on our experience.

I've verified I'm reusing charts, not creating a new one each time and causing memory leak. This is a Extjs 4 application.

30 Jul 2013, 4:29 PM
Are you running firebug at the time you're testing? With recent builds of Firefox / firebug I've seen that be extraordinarily slow - not framework related.

Regarding the memory issues have you looked in mem management (not sure what that is on Linux - Task Manager on Windows) to see if it's for sure the browser that's got the bloat issue? If so, with memory issues you might have to pare down the application to see if the fusioncharts are what's causing the issue or or if it's the use of ExtJS.

Also, are you using ExtJS 4.2.1 which should have the most up-to-date bug fixes?

1 Aug 2013, 7:30 AM
Thanks for reply. No Firebug, the Firefox forum talked about that browser not doing very good clean up after rendering stuff. It wasn't clear this even applied to this problem.

The plot thickened. We ordered another type of brick with more horsepower in main CPU and a graphics card, plus 4GB of memory. It ran imbedded Win 7 with IE9 browser. Out of box, it doesn't work at all. It takes a long time to do the initial render, then locks up entire browser while throwing errors the "server is not responding". There were no server issues. We launched Resource Monitor, the application was using 60-70% of CPU, even after it started throwing false server errors.

We then loaded Chrome browser on this Win 7 brick. It works like a charm, rendering performance equal to what I see on a full Win desktop. Resource Monitor showed CPU usage dropped to 20-30%. We let run all night last night with no issues.

So I think we have a working solution now. It would be nice to understand how these imbedded browsers really work on thin clients but that is way outside scope of this forum. Thanks again for responding though!