Install:

Intel HD Graphics http://downloads-us.dell.com/FOLDER00821733M/14

Then:

AMD Radeon TM HD 6470M/AMD Radeon TM HD 7450M http://downloads-us.dell.com/FOLDER00872259M/9

Unfortunately I tried the following drivers, but still not working:

Try Intel AutoDetect then ATI/AMD AutoDetect.

I tried the above mentioned autodetect applications.

1. In case of Intel it successfully updated the driver to the following version:

2. In case of AMD the driver update finished with an error:

"The AMD Catalyst cannot be downloaded due the computer does not have compatible hardware or software. The graphics adapter version is not supported."

Actually it is a false error, because if I download the latest Catalyst for HD 7xxx it could refresh the driver.

My feeling is that I need to wait while AMD/Intel releases the right driver for switchable graphics for Windows 8.

I tried more than 3 driver version in case of integrated and amd graphics card, and nothing seemed to be working under windows 8, however under windows 7 there were no problem with switchable graphics.

I also own a vostro 3350 with radeon 7400m graphics. I hope dell/amd will release the official driver soon. Anyway, for the time being, I found this engineering sample driver which work in my laptop:

http://drivers.softpedia.com/progDownload/AMD-Radeon-HD-7400M-Series-Display-Driver-89700-for-Windows-8-x64-Download-176335.html

Let try this in your laptop and see it's work or not. Hope it help.

I am using currently the following version of the driver:

What you suggested is a little bit older.

However there are still issues with this version too, sometimes its suddenly stops working.

I hope new version of the driver will resolve the issue. Just one more notification, the driver which is in the latest catalyst (2012 december beta) just does not work :)

I also have the same version as you. And I stop seeing the suddenly stop working message too.

What I do is just uninstall the dell amd radeon driver version including the catalyst, install the driver I mentioned, and install back the dell driver and catalyst. It's working well now :) anyway, thanks for the notification but I won't try when all is good now. I just hope the official version is available soon.

I checked the performance of the different drivers, and found the above (9.0.0.0) is the best.

However it is still a nightmare, and is so far from Windows 7 performance.

Actually it seems it takes a lot of time for Intel & AMD to resolve this problem.