RadHtmlChart is running very slow on IE8

[Wenjiang]

We have a  RadHtmlChart of around 30 series, it runs fine on Chrome, Firefox, and IE 9/10. But really slow on IE8. Is there anyway to improve performance on IE8?

[Danail Vasilev]

Hi Wenjiang,

RadHtmlChart uses a new approach of rendering compared to the old RadChart - it renders entirely on the client side through JavaScript by using SVG or VML, which are essentially forms of an XML document.

This means that there are a lot of elements (nodes) that need to be handled on the client which can cause slower browsers like IE7 and IE8 (especially when used on slower machines) to not meet all your needs.The charts will, however, continue to function properly and show the data, it is just that the browser does not manage to render them fast enough.

In addition, when the charts have their animations enabled (which is true by default) the properties of the multitude of nodes mentioned above must be changed rapidly. This, in turn causes the browser to re-render the image, which is an expensive operation. Now, when you multiply this effect five or six times for example, this will play a more significant role in the decreased speed of the rendering.

What I can suggest you in that case is that you simply remove the animation of the charts by setting the Transitions property to false. This is not a bug/issue in the control but a browser behavior in older ones that are simply slower.

Regards,
Danail Vasilev
Telerik