A new version of the beta is available for downloads. Please see the previous news posts on the DX8 beta if you are trying it for the first time.
The download is now about 800KB and is located here:
http://downloads.hitechcreations.com/AHDX8BETA4.EXE The changes in this version are-
Frame rate should be back up.
Alt tab should not mess up textures.
Disabled the detail texture for now.