Alienware m15x GPU dedicated vs integrated issues

I have been searching for a few weeks to the issue I am having but unfortunately I haven't run across any fixes for issues quite like mine.

Original setup of the M15x laptop was 300gb HDD, i3-330m dual core and Nvidia 240M GPU

I have since changed all of the above to a 1TB WD HDD, i7-640m dual core and an ATI mobility HD 5850 GPU

The install of Windows 7 Home premium, all Alienware progs and drivers for hardware went fine and all is working well except for the GPU.

Initially I tried to install the driver for the new card from the dell site for the HD 5850 card by flashing the BIOS but it did not take. I suspect that may be due to the driver from the site being for BIOS version A02 and I am running A09.

At that point device manager was only showing 'Standard VGA' under display. I am not able to locate any drivers for the Intel integrated GPU (most likely due to age) so I installed ATI Catalyst v.15.7.1 and subsequent drivers. The install went fine and the catalyst is useable, gaming is working also.

The problem is stealth mode doesn't appear to work any longer, nothing is shown in command center for stealth mode enabled/disabled, HWinfo monitor shows both the integrated and dedicated temps and process running in tandem. There is also no settings in the BIOs for video cards that I can see. I suspect it is either running both in a hybrid SLI mode (if thats even possible).

When I enable stealth mode the intel GPU runs and process just 1% above the ATI GPU and with it disabled the ATI card runs and process just 1% above the Intel gpu.

My concern is unnecessary load on the CPU on board gpu as well as possible throttling of the ATI card. Any help would be appreciated.