Intel OpenCL CPU runtime and Intel HD Graphics problem

Last update: A. Peternier, 15/12/2015

1. Automatically installed OpenCL runtime (Windows)

During the installation of SARscape 5.1+ under Windows, the user can select to optionally install the Intel OpenCL CPU-only runtime. When selected, the Intel OpenCL CPU-only runtime installation is performed silently (in SARscape version 5.1 and 5.2) or through the installation GUI (from SARscape 5.2.1 on).

2. Intel HD drivers and CPU-only runtime

Recent versions of the Intel HD Graphics drivers now include the Intel OpenCL CPU-only runtime during their installation/upgrade. The OpenCL runtime version provided through the graphics drivers is also more recent than the one available as stand-alone download from the Intel website or proposed by SARscape during the installation process.
Unfortunately, it seems that the Intel HD driver installation will not check for the presence of an already installed stand-alone version of the OpenCL CPU-only runtime, which leaves the runtime in a corrupted, non operational state (see the related discussion on the Intel forum).

3. Workaround

At the moment, the following procedure should fix the problem. Please be aware that this procedure requires the reinstallation of the Intel graphics drivers, which can leave your computer in an unusable state if not done correctly.

Uninstall the Intel OpenCL CPU-only runtime from your computer (you can do this through control panel>programs>uninstall a program).
Download the proper Intel HD Graphics driver from the Intel website. Make sure to download the driver as .zip instead of .exe.
Follow these guidelines to (re)install the updated Intel graphics driver.

In addition to the latest version of the Intel HD Graphics driver, you should now also have a newer version of the OpenCL CPU-only runtime (probably version 5.2.* or higher).