I can confirm that 11.8 Preview offered both 5x1-P and 5x1-L when I got into the CCC Eyefinity setup.
That being said, I had serious problems with installing 11.8 Preview. When I installed it, I lost the Catalyst Control Panel. If I downgraded to 11.7, I got it back. I followed
this article from the AMD KB, but to no avail. I believe the article is on the right path with it being an issue with the .Net and CCC interaction.
My nerd rage kicked in, in full. I did a complete wipe and reinstall of Win7 to get it to work. The one thing I noticed is this... On my previous install, I had components for .Net v1 and .Net v4 installed. However, I
*DID NOT* have .Net v3.5 installed. Upon the clean install and "Windows Update" routine, I had all three versions of .Net installed. With my first attempt to install the 11.8 Preview, it now worked...
If you are having problems installing a Preview/Beta version of the driver, I would suggest checking your installed components/programs and see if .Net v3.5 is installed. It can be manually installed by
downloading from Microsoft.
Just to note, this is the first problem I've had installing an ATI/AMD driver. I've installed every available driver (since I installed Win7), one on top of the other. This includes every release, preview and beta driver. It also accounts for swapping cards frequently to do all the testing and benchmarking for the WSGF.
In the end, 5x1 users finally have a real driver update in the 11.8 Preview. I called my contact at AMD about the update in this driver, and his response was that to this point the 5x1 support was considered beta and wasn't included in every driver update. It had been included in the non-WHQL drivers (10.12 and 11.4 Preview). This 11.8 Preview will provide all of the recent performance updates from the "Mjölnir" initiative. He also confirmed that their goal is to have the 5x1 support in the release drivers during Q4 2011.