I understand that you are having problems utilizing your Solid-State Drive for accelerating your hard drive.
At this time I recommend to backup all the information that you have on the Solid-State Drive that you wish to use to accelerate the hard drive and perform a low level format.
After this make sure that you are using the BIOS version 0028. If not please update your BIOS to this version.
Here is the BIOS update download: http://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=20965&ProdId=3381&lang=eng&OSVersion=%0A&DownloadType=BIOS
Try to aceelerate the hard drive.
If the problem continues, you need to make sure that you have the SATA configuration as RAID.
thanks for your answer, but I am already using the latest BIOS with SATA controller configured to RAID mode.
The SSD is also already successfully configured to be used as the cache device by the windows tool. This is also shown by the RAID bios.
The only missing thing is, that the magnetic HDD is shown in the drop down box of HDDs to be accellerated, but if I press the ok button, to confirm, the HDD is not taken over to the overview screen and the RAID bios also shows me, that no accelleration is activated for that HD.