The way Rhino “detects” any of this stuff is through the use of the MMC and Registry keys. In some instances that information can get messed up or even exist in completely different areas or even exist in slightly different formats. Unfortunately there are no well defined function calls that can be made to get this information, it’s more of a hunt-and-peck approach. Obviously there’s a way to get the information correctly and consistently since the OS seems to be able to do it, but so far I have found no single method that works on ALL OS’ and SPs. XP was/is the worse.
That being said, it really isn’t anything to worry about. This is just text information being filled in, coming from other text information within the Registry. Most of the time it works and is consistent with what the OS says, but if/when things don’t match with the OS, it doesn’t mean that Rhino won’t use all available memory…it just means Rhino’s dialog is getting the information wrong. I realize it can be confusing, but the OpenGL settings page is primarily supposed to be used for diagnostic purposes and not for system info or validation.
I will look into why things seem to be wrong more often than not on Window 8…but for now, please don’t hang any weight or importance on the information you see in Rhino’s OpenGL settings page (other than the configurable options).