When using a touch screen device such as Microsoft surface pro which utilizes the full receiver for windows client users notice a delay when using the touch screen swipe feature in the session. This delay is most obvious when using the finger or a stylus pen to draw in an application such as MS Paint. When drawing a line from left to right users will notice that the first part of the line will not produce any output.

This issue is only reproducible in HDX sessions on server 2008 R2 VDA. The issue is not visible on Windows Server 2012 R2 VDA's.

There is no solution for VDA's running 2008 R2. If this issue is critical then you will need to update the VDA to 2012 R2 to enable support for multi-touch.

Possible workaround is to utilize the HTML5 receiver client as this uses different functionality and does not show the issue.

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Problem Cause

The behaviour of seeing approximately a 450ms delay for a touch swipe on Server 2008 R2 is expected behaviour.

For Windows Server 2008 VDA, when receiver receives the first WM_TOUCH (https://msdn.microsoft.com/en-us/library/windows/desktop/dd317341(v=vs.85).aspx) message, it starts a timer to decide whether it's a swipe or not. The length of the timer is 450ms. Only when the timer expires, VDA can be notified for the swipe event.

For Windows Server 2012 (and beyond), the multi-touch feature is supported. A special ICA channel is introduced for touch usage. So, it uses a different logic and the delay is not introduced. But unfortunately, Windows Server 2008R2 is not supported for multi-touch feature